Kitchen Project #177: Buttery Tomato Pie
+ guide to buying tomatoes by Jordon King
Hello,
Welcome to today’s edition of Kitchen Projects. Thank you so much for being here.
We are at the height of summer and I know you might be thinking more about berry, or peach pies right now, but I hope I can convince you to give this buttery tomato pie a go. This recipe highlights the absolute iconic marriage of tomato and butter and, jus to gild the lily, I’ve also got the wonderful cook and writer Jordon Ezra King stopping in to give us a guide to tomatoes - what to buy and how to use them!
For KP+, the tomato madness continues. I was experimenting this week and am thrilled to share the recipes for tomato caramel (chewy candies AND sauce… plot twist… they are the same recipe but with different technique. Madness) as well as beautiful candied cherry tomatoes. Click here for the recipe.
What’s KP+? Well, it’s the level-up version of this newsletter. By joining KP+, you will support the writing and research that goes into the newsletter (including the commissioning - and fair payment - of all the writers), join a growing community, access extra content (inc. the entire archive) and more. Subscribing is easy and only costs £6 per month or £50 for the whole year. Why not give it a go? Come and join the gang!
Love,
Nicola
A Slice of Summer
A few months ago I sat down with the ever-wise Milli Taylor to discuss menus and workshop ideas for Sobremesa, our cooking & food retreat in Málaga in August. Of all the glorious, sun-kissed ingredients at our disposal, Milli was quick to warn me of two, possibly crucial gaps in my usual baking arsenal: Butter and cream.
Of course you can get butter (mantequilla!) and cream (crema!), but for very reasonable climate reasons, it is not a butter-focused cuisine, and the local availability reflects that. Plus, who wants to come to Spain and learn British tea time baking, or battle with pastry that disintegrates in your hands?
Olive oil, however, is plentiful. And where butter can feel like a cosy blanket, a slick of grassy olive oil can gently brighten and round out flavours. Plus it doesn’t melt when you touch it because… it is already liquid. Ha!
So, for my workshop in Spain next month, I wanted to develop an olive oil pastry - flaky, flexible and flavourful. Crucially, I had also been dreaming of a double-crusted tomato pie, a summery marriage of the season’s best sweet cherry tomatoes and flaky pastry. Tomatoes are fruits, after all; why not give them the pie treatment? Could the flaky olive oil pastry of my dreams be the perfect match?
Plot twist: I managed to develop an absolute workhorse of a flaky olive oil pastry BUT when it came to this week’s recipe, it just wasn’t to be: Though tomato and olive oil might seem a more classic pairing, the hero love story this week is tomato and butter. Perhaps it sounds unfamiliar on the surface, but when you consider the character… rich fatty dairy plus acidic fruit, you’ll surely think of hundreds of beloved examples; Tarte au Citron, Rhubarb pie, a tangy citrus Cheesecake, Scones with cream and tangy jam.
So, I’m very excited to share a recipe for a rustic tomato slab pie, stuffed with sweet, popping cherry tomatoes and gooey, umami onions cradled by flaky, buttery pastry. But before that, you’ll be treated to an excellent guide to tomatoes by my friend, chef and tomato scholar, Jordon Ezra King.
Over on KP+, I’ve been thinking a lot about tomato juice. Knowing that I’ll have plenty of excess tomato water/juice from making copious pan con tomate in the coming weeks, I wanted to figure out a fun way to use them. Enter: Tomato caramels and candies. I’ve long loved the combination of tomato and vanilla thanks to Claire Dinhut and her tomato, vanilla and basil jam. So, cooked into a candy (sans basil), these are a delight. I’ve also shared the technique for tomato caramel sauce, which can be drizzled over vanilla ice cream and served with candied tomatoes for an unforgettable and unique summer dessert:
But first… a guide to picking the best tomatoes, and what to use them for. Over to Jordon!
A Cook’s Guide to Fresh Tomatoes
How to choose the right tomato for the right dish
Tomatoes are one of the defining ingredients in the food I cook. In fact, they’re my favourite vegetable (fruit, I know). I probably eat them, in some shape or form, every single day. Because they come in such a wide range of varieties, there’s a lot of choice out there when picking the best type of tomato for the recipe you’re making. Shape, flesh, seeds, skin, water content and sweetness all play a role here. Whether you’re roasting them, blending them into a sauce or slicing them up for a salad, having a bit of understanding on what to look for is really helpful. Here’s your guide to buying and using fresh tomatoes well.
Seasonality
Peak tomato season in the Mediterranean (and in Europe in general) typically occurs in mid-to-late summer. This is when markets bulge with brilliant red orbs of all shapes and sizes, and the air smells of their green vines. In fact, a ripe tomato, challenged only by a ripe peach, is the most sensual thing in the market. All curves and scent and thin skin that bursts at the whisper of your teeth.
Out-of-season tomatoes, often grown under glass and picked underripe, lack aroma and sweetness. A supermarket tomato in December is a sulky little fraud, the colour of optimism but the flavour of wet cardboard, bred to survive a journey rather than a fork. It sits on the plate like a plastic bauble pretending to be summer.
If it’s winter and you must have tomatoes, you have two options. In the supermarket, small varieties like cherry will be better than the large, although still not the same as in summer, or you can look for ‘winter tomatoes’ from a specialty supplier. These are varieties like camone and marinda, which grow in coastal regions of Southern Spain and Italy are in season from November to April. They’re a different flavour profile to summer tomatoes, savoury, saline and delicious, and much better than eating summer tomatoes in the winter, if you follow.
At the moment of writing (mid-July) we have had good tomatoes for a month or so, but we’re now really getting into peak season. This is when it gets exciting. For the next two months, eat as many of the good ones as you can.
Tomato Types and How to Use Them
1. Plum Tomatoes (San Marzano, Roma, Datterini)
What They’re Like: Oblong, meaty, low in seeds and juice.
Season: July to September.
Why: These are the workhorses of sauces. San Marzano, grown in volcanic soils near Naples, are the gold standard because of their balance of sweetness and acidity and their ability to cook down into a dense, velvety pulp. Datterini look like cherry/ grape tomatoes (see below) but their characteristics (higher proportion of flesh and fewer seeds) place them closer to plum, just smaller.
Best Uses: Sauces, soups and slow braises.
Buying Tip: Firm but not rock hard, avoid any that feel spongy.
2. Beefsteak Tomatoes (Cuore di Bue, Marmande)
What They’re Like: Large, ribbed, full of juice with tender flesh.
Season: High summer.
Why: Ideal for raw dishes where you want a bit of heft. Think panzanella, fattoush or a caprese. Their mild sweetness and generous juice soak into bread beautifully.
Best Uses: Thick slices or chunks in salads, layered with mozzarella or stacked onto toasted bread.
Buying Tip: Heavy for size, deeply coloured, and aromatic at the stem end.
3. Cherry and Grape Tomatoes
What They’re Like: Bite-sized, round or grape shaped.
Season: Peak in summer, but better year-round compared to larger tomatoes (see above).
Why: Their concentrated sweetness makes them great in quick dishes, think speedy spaghetti or little tomato tarts. Their high sugar content means they caramelise well in a hot oven or grill.
Best Uses: Toss in salads, blister in olive oil for a fast pasta sauce, roast with anchovies and herbs for a crostini topping.
Buying Tip: Look for vibrant colour, taut skins and no wrinkles.
4. Heirloom Tomatoes (Costoluto Fiorentino, Green Zebra, Purple Cherokee)
What They’re Like: Irregular shapes, thin skins, wide variety of colours.
Season: Late summer. Fleeting and precious!
Why: Each variety offers its own nuance. Green-tinged can be citrussy, dark reddy purple can be earthy and winey. Perfect for showcasing raw in dishes like a tomato carpaccio.
Best Uses: Salads, open-facing sandwiches; simple plates where the tomato is the star.
Buying Tip: Judge by smell and firmness, not just how pretty they are!
5. Bonus: Green (Unripe) Tomatoes
What They’re Like: Hard and green, maybe with tinges of red at the stem end.
Season: More common in early summer or autumn.
Why: Green tomatoes are just regular tomatoes which haven’t ripened. This can happen if they fall off the plant early, or due to frost.
Best Uses: Frying, pickling, chutneys.
Buying Tip: Don’t confuse them with certain heirloom varieties that are green when ripe. Those will feel softer and smell sweet. You can’t really buy green tomatoes like this, but if you grow your own then you’re bound to end up with some. Don’t throw them out! Look up some traditional uses like pickles, chutneys and fried green tomatoes.
How to Choose
Feel: Heavy for their size means juicy. You want taut skin with no bruises or wrinkles.
Smell: A sweet, grassy aroma near the stem means ripeness. It sounds obvious but they should smell like tomatoes.
Color: Rich and even. Pale shoulders (the area around the stem) suggests under-ripeness.
Avoid: Bruises, cracks or a mushy texture. One exception are stress lines or scarring that you will sometimes see on high quality tomatoes in season. These are a sign of careful water management where the farmer has restricted watering enough to ‘stress’ the plant and concentrate flavour and sweetness.
Storage and Prep
Never refrigerate ripe fresh tomatoes if you can avoid it. It dulls the flavour and gives them a mealy, floury texture.
Store with the stems still attached in a cool, dry place.
For maximum sweetness, let underripe tomatoes sit in a paper bag at room temperature for a few days, put a ripe banana in there to speed it up!
With fresh tomato dishes, chop them up, salt them generously in a bowl and leave for 15/20 mins, then drain the excess liquid (Editors note: Keep this liquid - you can make caramels, candies etc with it). This will season them properly all the way through and makes a huge difference.
Basil is the obvious choice but play around with other herb pairings like fresh oregano or tarragon for a Southern French style salad.
Hopefully you find this guide useful and are inspired to seek out this wonderful fruit in all its flavours, shapes and sizes. One final note, because I know somebody will ask; what’s my favourite? Cuore del vesuvio (Vesuvian bullsheart). They grow in the volcanic, mineral rich soil around Mount Vesuvius and have a very high flesh to seed ratio. Amazing cut into big chunks for a salad, grated onto bread or cooked down into a sauce.
Jordon King is a cook, writer and recipe developer based in London. You can read his writing at A Curious Cook.
Olive oil vs. Butter
This week, I really did think I’d be writing all about using olive oil in pastry and sharing the recipe with you. While the full the story of developing the olive oil pastry will have to wait for another day, this does have a happy ending. (And for any KP readers coming to the retreat and likely making this pastry, that means there are no real spoilers ahead!)
Throughout the olive oil tests, I kept my classic buttery pie dough as a control and comparison. I am not plant-based, so I had no desire to create a recipe for olive oil pastry unless it could genuinely hold its own against my classic recipe. Of course, they don’t need to do the same thing exactly, but I never develop recipes for the sake of it - we all suffer that way.
As my tests continued, the olive oil pastry really began to give the buttery one a run for its money. What started as a grissini-esque, slightly dry and not very tender cracker-like dough ended up as a rich, flaky, and flavourful pastry. I was thrilled. But I knew my ultimate development goal this week was to share a recipe for tomato pie and once combined with the filling, the butter pastry was blowing the olive oil out of the water.
The Tomato Pie
Depending on where you stand and who you ask, tomato pie is a term that describes a variety of dishes. To many communities in the US, a tomato pie means a pizza. In New York it might mean a thin crust with a little cheese, while in Philadelphia, it might have a thicker plusher base, reminiscent of sfincione (recipe on KP!), with a rich cooked tomato topping. In the US South, a tomato pie is not a pizza at all… It’s back to being a pie. It uses a classic, rich, buttery crust and usually combines tomatoes with cheese. In Cheryl Day’s ‘Treasury of Southern Baking’, the ‘Summer Tomato Pie’ has both heirloom and cherry tomatoes and is mixed with caramelised onions, mayo (a traditional ingredient of the Southern Pies, my research reveals) and two types of cheese, along with basil and thyme. In Europe, the tomato tarts are more likely to be simple, single-layered affairs. In France, a tarte aux tomates may have a little Dijon and herbes de Provence, while here in the UK, I’ve rarely seen tomatoes in a tart case unless it was in the form of quiche.
Though I tried to fit the square peg (flaky olive oil pastry) into the round hole (tomato pie) of this week’s newsletter, I gave in to the masterful combination of buttery pastry with tomato. This isn’t my first rodeo - the tomato and fennel tart tatin in SIFT is one of my favourite recipes. But there it is bolstered with intense caramelised flavours and the aromatic fennel - what happens if we just strip it back to basics?
Butter and Tomato
Even though butter and tomato isn’t an out-of-the-ordinary combination, it sometimes evades my flavour radar. The best tomato sandwich is made with mayo, not butter, and pan con tomate, with its grated fresh tomato, is best with a glug of olive oil.
Once I started pulling the butter/tomato thread, I realised there were plenty of beloved buttery tomato combinations out there: Cream of tomato soup, Butter Chicken (a recent invention - 1950s!) and, of course, Marcella Hazan’s famous tomato butter sauce (a northern Italian classic, according to Jordon King, that was popularised by Hazan in 1973) which sees an onion halved and bathed in tomatoes and butter as it cooks to create the most beautiful, simple sauce. In cooking, we know that opposites can attract, so butter and tomato are actually an obvious match - juicy, acidic tomatoes with rich, creamy butter – the two balance each other out marvellously. So why is it such a seemingly underrated combination?
I asked tomato scholar Jordon King for his opinions on why this might be. His guess? Perhaps the Venn diagram of the regions that have both good butter and good tomatoes is relatively small. Once such outlier, he points out, however, is France. Dishes like Tomatoes a la Creme, literally just tomatoes halved, seared, then reduced in cream, have long championed the combination.
The challenge is… to keep things simple
As tempting as it was to introduce cheese into the mix, I made a promise to myself to try to keep things simple. Taking inspiration from Marcella Hazan's sauce, I decided to commit to just three flavours: Butter, Tomato, and Onion. The butter was taken care of in the pastry, and sweet, popping cherry tomatoes seemed to make the most sense in the pie format. Now the only thing left to organise was the onions.
I love caramelised onions as much as the next person, but waiting for them is painful. Properly caramelised onions, which have just three ingredients - onions, butter and salt - can take hours to prepare properly. I would say at a minimum, you’re looking at an hour, and you’ll need to be babysitting them the whole time. This week, I decided to take a shortcut to those intense, sweet and savoury flavours with the help of my pantry. Once the onions are softened (just ten minutes with the lid on with a pinch of salt and some butter), adding a mixture of light brown sugar, light soy sauce and fish sauce (or anchovies if you like – or omit if you’re veggie!) then reducing for another 5 minutes gives you an intensely flavoured base with much less effort than caramelising them ‘properly.’
You could certainly dress this pie up - the filling could include olives, capers and a little spice to make it reminiscent of a puttanesca, or add basil or tarragon.. but sometimes the challenge is just to leave things be and appreciate the simplicity.
Starch
When it comes to fruit pies, the addition of starch is essential; When heated, the cell membranes of fruit begin to break down and the water escapes, releasing juices. Without a net, in the form of starch, which thickens when hydrated and heated, things get very messy indeed.
Tomatoes are some 95% water, which means we need a game plan when cooking with them, especially if we want any chance of a crisp pastry base and top. In fact, in Sauce Tomat - one of the classic French mother sauces codified by Escoffier - the tomato sauce utilises a roux base to create a thick texture! I baked a few tests, some using starch, others using a gooier onion with more liquid, to see what worked and it was immediately clear that I needed to use starch in this recipe. The final head-to-head was in the large format, with flour heading off against cornstarch. In the end, the ever-reliable cornstarch won - the set was tender but solid. Perfect for transporting and slicing til your heart is content.
The finish
Perhaps it was the heat this week, or perhaps it was my commitment to keeping this recipe as simple as possible, but I decided to use the ever-reliable format of a slab pie (a pie baked in a baking tray) for this recipe. Slab pies are quite rustic; they have a narrow profile and are impressively transportable. These veer into galette (des rois) or pithivier territory, except they have the useful structural support of a tray.
I was tempted to do lattice work or a fancy crimp, but in the end, I wanted this recipe to be an un-intimidating workhorse that you can throw together with minimal stress. Also, my kitchen was 31c on Friday and I gave up trying to do anything fancy if I’m honest. If you wanted to dress it up for an occasion, you could sprinkle sesame or caraway seeds to give a little texture to the pastry, or make a 1.5x batch of the pastry to make a lattice top.
A big success factor of this pie is the bake - it needs to be baked thoroughly to have a pleasing and robust base. As an insurance policy, I pre-heat the oven very hot with a tray inside and then turn it down immediately when the pie goes in. I have also altered my regular pie dough recipe to use water only, which gives you a crisper finish compared to my usual recipe which uses creme fraiche as well as water.
RECIPE: Buttery Tomato Pie
Makes a 9x13inch pie, enough for 8 lunch-y slices, or 10-12 picnic snack slices.
Pie dough (You could use shop-bought puff for this, good quality of course, if you want!)
330g Plain flour
20g Caster sugar
7g Fine sea salt
250g Unsalted butter, cold
120g water, cold
Umami Onions
3 Medium white onions, about 550-600g (weight 500g once prepped)
25g Unsalted butter
Large pinch of salt
2 tbsp Light soy sauce
1-2 tbsp Fish sauce*
30g Light Brown Sugar
*You can sub this for 1 anchovy, packed in olive oil, which you add at the beginning with the butter. OR, just omit completely then retaste and adjust with soy sauce and salt.
Tomato filling
650g Cherry tomatoes
325g Umami onions (any leftover from above can be stored in the fridge, eaten on toast, etc!)
30g Cornstarch
½ tsp Flaky salt (optional - taste your onions, if they are very intense, you can omit this salt)
Plus: 1 egg, whisked with a pinch of salt for Egg wash
Method
For the pie crust: Follow the directions for flaky pie dough here. OR make in the food processor - it has a few less layers, but good method for a heatwave: Pulse the dry ingredients together then add the cold butter, cubed into 1-2 inch pieces. Pulse until the butter is in small, pea-sized chunks - a few different sizes are okay! Add in the liquid, then pulse for about 20 seconds until the dough forms clumps. Place a piece of baking paper or cling film on your work surface and transfer the dough clumps onto it - gently bring the clumps together into a cohesive piece of dough as you enclose the paper/cling film. Once sealed, gently roll over it with a rolling pin to form it together.
Optional step: Chill for at least 1 hour until somewhat firm, then roll into a rough rectangle about 2.5cm thick, cut into thirds, then stack back on top of each other to create some layers. Rewrap the dough, pressing down on so it is about 2.5cm thick and leave to chill for another 1 hour or until firm before using.
For the Umami onions, slice the onions thinly, about 3mm. In a large saucepan that you have a lid for, heat the butter on a high heat until foaming then add in the sliced onions, followed by the salt. Stir the onions to coat them in the butter then put the lid on the saucepan and turn the heat down to low. Cook for 10 minutes - the steam should help the onions soften and collapse.
Remove the lid (careful of the steam!) then stir in the sugar, soy and fish sauce. Taste and adjust - it should be very tasty but you can add more salt/soy/sugar/fish sauce to meet your umami needs. Bring the temp back to medium and cook for 3-4 minutes or until most of the moisture has evaporated and when you drag a spatula or wooden spoon through the onions, it won’t re-fill quickly with liquid. Move into a clean container and leave to cool completely before using / you can store in the fridge for 5 days.
For the pie filling, halve about 1/3rd of the cherry tomatoes, and score another third - not too deeply, just so the liquid can come out (and the seasoning can penetrate the tomato!) and leave the rest whole. Mix with the onions, the flaky salt (check taste of onions first as this is optional) and cornstarch.
To assemble the pie: Take a 9x13inch baking tray (aka quarter sheet pan. it doesn’t have to have tall sides - this is a shallow pie) and, if it looks like it might stick to your pie, place a little greaseproof paper in the base (though direct contact to metal will give you the best pie)
Divide the pastry into ⅓ and ⅔ pieces (approximately 450g and 250g) and re-wrap the smaller piece, then leave it in the fridge. Roll out the larger piece to 3mm thick rectangle, about 40cm x 27cm. Transfer to your baking dish. Pour in the filling then place it all in the fridge whilst you roll out the top.
Roll out the top piece to about 20x30cm. Get your pie from the fridge then lay the piece of pastry on top and tuck it around the tomatoes. Trim the edges of the overhanging base pastry, then fold over the pastry sides to enclose the pie and press gently to seal. Chill the pie in the fridge for 30-40 minutes, or the freezer for 15.
Preheat the oven to max (mine is 240c fan) and place a baking tray inside to heat up. When the pie is chilled, egg wash then cut a few vent holes on the top with a sharp knife.
Place the pie on the preheated tray, turn the oven down to 180c fan then bake for 50-60 minutes until very golden. If you find it is burning or colouring too quickly, you can reduce the temp to 170c,or tent with foil.
Leave to cool for about 1hour before slicing and serving with a simple green salad.
As for caramelised onions, if you happen to have a pressure cooker, slice the onions using a food processor and cook them for 5 minutes with salt, butter, and a bit of water. Then uncover and reduce the liquid along with the onions until it caramelises.
You’ve just saved yourself an hour
Wow! Amazing and thorough article on creating this lovely tomato pie! Had never heard of candied tomatoes or tomato caramel sauce ever before, but will now try making both, as well as the pie, which I think my husband will love!😋 Thank you for sharing the recipes!