Heirloom tomato tart
Late August & early September sees the kitchen counter filled with garden bounty, the most treasured of which is the heirloom tomato, its imperfect spherical shape & unmistakable scent epitomizing the height of this much-loved season. Delicious simply sliced & lightly salted, the heirloom tomato is a staple in our small but productive vegetable patch. Although best enjoyed without much fuss, I ventured from the classic caprese & traditional salads several years ago with a baked heirloom tomato tart, & I’ve been making this favorite tribute to summer every season since.
Throughout August & September I bake this exact tomato tart at least four times. It’s my absolute favorite way to eat the sweet yet herbaceous fruits from our garden & quite honestly, the season of long days & sunshine would be incomplete without it now. In fact, a couple of dear friends feel the same way & as soon word is out that my homegrown tomatoes are ripe, they’re on the phone without hesitation!
With just under a week until the sun sets on Labor Day, it feels as though this summer is rapidly drawing to a close. My raised vegetable beds tell a different story, however, & with my favorite heirloom tomatoes continuing to thrive, the season is far from finished according to them.
Join me in squeezing out every last drop of summer this year. Get your hands on some heirloom tomatoes in the next week or two & add this favorite recipe to your repertoire. I promise you won’t regret it!
Heirloom Tomato Tart
Prep time: 2 hours
Cook time: 45-55 minutes
Serves: 8-12 portions
ingredients
For the pastry:
200g plain flour
125g cold butter, cut into cubes
1/4 tsp salt
1 large egg
2 tbsp ice-cold water
For the filling:
2 large red onions, peeled, halved through the root & sliced thinly into 1/8-inch thick slices
1 tablespoon butter
1 tablespoon olive oil
3-4 ripe heirloom tomatoes, sliced into 1/4-inch thick slices
A handful of cherry tomatoes, sliced in half
100g feta cheese
Fresh thyme
instructions
First, make the shortcrust pastry. Pulse flour & salt in a food processor until blended, or mix with a spoon if making by hand.
Add cold, cubed butter to the food processor & pulse 8-10 times until mixture forms pea-sized pieces. If making pastry by hand, gently rub the butter into the flour using your thumbs & forefingers until the mixture resembles large, moist breadcrumbs.
Beat together the egg & ice-cold water, then with the processor running on low, slowly pour the liquid into the flour mixture until it begins to come together. Be careful not to over mix the dough, it should just start to form a larger mass when pressed together. If making the pastry by hand, “cut” the liquid into the flour mixture using a butter knife. When a dough starts to form, use your hands to gather it into a larger mass.
Turn the dough out onto a clean surface, wrap completely in plastic wrap & flatten with the palm of your hand to form a disc. Place in the fridge to rest for an hour. Meanwhile, prepare the tart filling.
In a large, wide, heavy-bottomed pan, heat butter & olive oil over medium heat until melted & sizzling.
Begin adding the sliced onions. Instead of throwing them all in at once, start by adding just a couple of large handfuls. Cook, stirring, until the onions are soft & starting to turn translucent, 1–2 minutes. Stir in a few more handfuls of onion & repeat cooking & stirring until all the onions are added. Season with a pinch of salt.
Reduce heat to medium-low & continue cooking onions, stirring every few minutes to prevent them from sticking & coloring too much in any one place. Cook for 20-30 minutes until the onions are nicely caramelized. As most of the water has cooked off after about 10-15 minutes, there might be some spots where the onions may begin to stick & burn. If this happens, stir in a splash of water. The liquid will dissolve the cooked-on bits, which the onions will re-absorb.
Once caramelize, sweet & jam-like, remove from the heat & allow to cool completely.
When the pastry has finished resting, unwrap & place on a lightly floured surface. Gently roll into an 11” circle. Using the rolling pin, gently drape the rolled out pastry over a 9” (23cm) fluted tart pan with a removable bottom. Carefully press the dough into the base & up the sides of the pan.
Drape the excess pastry over the edge of the pan without tearing. This helps to prevent shrinkage.
Lightly prick the bottom of the dough with a fork, then cover & place in the fridge for up to an hour. Preheat oven to 400°F / 200°C convection. If using a conventional oven setting, preheat the oven to 425°F / 220°C. Place a baking sheet large enough to accommodate the tart in the oven to preheat also.
While the uncooked tart is resting, layer the sliced tomatoes in a large colander & salt generously, making sure to salt every tomato. Place on a plate or over the sink to allow the juices to escape. This step is crucial for extracting water from the tomatoes so that the pastry stays crisp.
After an hour, remove the chilled tart from the fridge & carefully line the inside with baking parchment. Fill with pie weights or dried beans.
Place on the hot baking tray in the oven & cook for 15-20 minutes. After 15-20 minutes, very carefully remove the pie weights by lifting the baking parchment up out of the tart. Set the parchment & pie weights aside & continue to cook the tart for a further 5-8 minutes until evenly browned.
Once partially cooked, remove the tart from the oven & reduce the temperature to 350°F / 180°C convection. If using a conventional oven setting, reduce the oven to 375°F / 200°C.
Fill the bottom of the tart with the caramelized onion confit. Gently place the sliced heirloom tomatoes on top, filling in any gaps with halved cherry tomatoes for a nice even layer. Crumble the feta cheese into bite-size pieces atop the tomatoes & finish with a sprinkling of fresh thyme.
Bake in the oven for 25-30 minutes until the feta begins to brown. Slice & serve warm with fresh greens dressed in balsamic vinegar if desired.
