But where roasted tomatoes really shine is in a tart. When you bake a tart with fresh tomatoes you have to deal with that awful watery tomato juice mess which causes the tart base to get soggy and turn into mush. We don't want a mushy tart. We want crispy and buttery and tender! Roasted tomatoes solve that problem and also provide an extra element of flavor i.e. unmami and we love unmami.
This tart takes some time, but it's mostly hands-off which makes it an ideal weekend project. Slow-roasted tomatoes get nestled in a buttery crust along with aged cheddar and a mess of caramelized onions and basil. It's true fall comfort food and the kind of thing you crave while you still have tomatoes at the market.
Roasted Tomato-Basil Tart
Recipe from Leites Culinaria
For the Slow-Roasted Tomatoes
2 pounds plum tomatoes (or smallish heirloom tomatoes of any sort)
1/4 cup extra-virgin olive oil
1 tablespoon finely chopped fresh rosemary
Salt and freshly ground black pepper
For the Tart Dough
1 cup all-purpose flour, plus more for the work surface
1/4 teaspoon salt
6 tablespoons unsalted butter, chilled and cut into small pieces
4 to 5 tablespoons ice water
For the Tart
2 tablespoons extra-virgin olive oil, plus more for drizzling
1 large yellow onion, thinly sliced
Salt and freshly ground black pepper
1/2 pound St. George or medium-aged white Cheddar cheese, shredded
1/2 cup chiffonade of fresh basil (that means cut into long, narrow strips)
2 tablespoons crème fraîche
1 large egg mixed with 1 tablespoon whole milk
Make the slow-roasted tomatoes: Preheat the oven to 225°F (107°C).
Cut each tomato in half crosswise. (Alternatively, if using large plum tomatoes or any size heirloom tomatoes, thickly slice the tomatoes crosswise into about 4 portions.) Arrange the sliced tomatoes, cut side up, on a rimmed baking sheet. Drizzle the tomato halves evenly with the olive oil, sprinkle with the rosemary, and season with salt and pepper. Roast the tomatoes until the moisture is completely removed, 4 to 6 hours, depending on the size of your tomatoes. The tomatoes should be dry but still soft to the touch, and when you press a tomato with your finger, it will feel plump yet exude no liquid. (If using sliced tomatoes instead of halves, you may wish to start checking them at 2 hours.) Remove from the oven and let the tomatoes cool completely.
Make the tart dough: In a bowl, whisk together the flour and salt. Scatter the butter over the flour mixture and, using your fingers, gently press the butter and flour together until it resembles a coarse meal. Drizzle the ice water over the top and, using a fork, gently toss and stir just until the dough comes together in a cohesive clump.
Gather the dough into a ball and place it on a lightly floured work surface. Flatten the dough into a thick disk and wrap in plastic wrap. Refrigerate for at least 1 hour and up to 2 days.
Assemble the tart: Position a rack in the lower third of the oven and preheat it to 375°F (190°C).
In a sauté pan, heat the 2 tablespoons oil over low heat and stir in the onion. Cover and sweat over low heat for 10 to 15 minutes, until the onion is soft and translucent. Do not allow the onion to color. (Alternatively, if you prefer properly caramelized onions, you can uncover and cook the onions until golden brown and intensely flavorful.) Remove from the heat, season with salt and pepper, and let cool completely.
Line a baking sheet with parchment paper. On a lightly floured work surface, roll out the dough to a round about 12 inches in diameter. Carefully transfer the round to the parchment.
Layer half of the cheese on the dough round, leaving a 1-inch border uncovered around the edge. In a small bowl, combine the cooled onion, the basil, and the crème fraîche and mix well. Spread the onion mixture evenly over the cheese layer. Top with the roasted tomatoes, then cover with the remaining cheese. Season with salt and pepper and drizzle with olive oil. Fold the uncovered edge of the tart onto itself, forming uniformly spaced pleats every few inches around the perimeter. Brush the overturned edge of dough with the egg wash.
Bake the tart for 30 to 40 minutes, until the crust is a nice golden brown. Remove the tart from the oven, transfer it to a wire rack, and let it cool until it’s warm or at room temperature. Slice and serve.