Crostata is a typically Italian dessert, a free-form tart made with whatever fruit is ripe and bountiful. Though this tart is a touch on the savory side, serve it topped with a dollop of sweetened whipped cream, and it's a great dessert.
12 ounces (about 2 1⁄2 cups) all-purpose flour, plus more for rolling
1⁄4 cup granulated sugar
1 teaspoon baking powder
1⁄2 teaspoon kosher salt
8 tablespoons (1 stick) cold unsalted butter, cut into cubes
3 large eggs
2 nectarines or peaches, pitted and sliced 1⁄2 inch thick
2 cups halved, mixed cherry tomatoes, such as Sungold and Large Red Cherries
1 tablespoon balsamic vinegar, plus more for garnish
1 tablespoon torn fresh mint leaves, plus whole leaves for garnish
1 teaspoon sugar
1 teaspoon kosher salt
2 tablespoons cornstarch
2 tablespoons sliced almonds
To make the dough:
Combine the flour, sugar, baking powder, salt, and butter in a food processor. Run the machine in 3-second bursts until the butter is cut into small bits (about pea-size).
Separate one of the eggs and set aside the white. Beat the yolk with the remaining 2 whole eggs. Add the beaten eggs to the flour mixture and process again in short bursts until a ball begins to form. It should still be broken and uneven.
Turn the mixture out onto a work surface and gently squeeze it together to form a ball. Press it into a thin disk and wrap it tightly in plastic wrap. Refrigerate for at least 30 minutes, or up to 48 hours, before rolling.
When you’re ready to bake, preheat the oven to 350°F.
To make the filling:
Combine the nectarines, tomatoes, balsamic vinegar, mint, sugar, and salt in a large bowl. Gently mix with a spatula. When it’s well mixed, sprinkle the cornstarch over the fruit mixture and continue mixing until it has been absorbed.
Clear a large area on your work surface for rolling out the dough and lightly flour the surface. Or cover the work surface with a large piece of parchment paper and lightly flour it. Place the dough disk in the center and roll it out into a large circle; it should be 1⁄4 to 1⁄2 inch thick and 18 to 20 inches in diameter.
Always roll from the center of the dough out toward the edge. It is best to always roll in one direction, then lift and rotate the dough, rather than turning the rolling pin. If the dough is sticking to the surface as you roll, add more flour in small increments or roll the dough on lightly floured parchment paper.
If the dough is not yet on a piece of parchment paper, carefully transfer it to one. Brush the entire surface of the dough with the reserved egg white. Using a slotted spoon, pile the filling in the center of the dough, making sure to maintain a 3- to 4-inch border of dough around the filling on all sides. Set aside the remaining juices in the bowl.
When all of the filling has been added, fold one side of the uncovered dough over to partially cover it, then rotate the crostata and fold another side. Repeat until all of the dough has been folded up around the edge and there is a large area of exposed filling in the center of the tart.
Transfer the crostata, on the parchment paper, to a baking sheet. Pour the reserved juices into the center of the filling. Brush the surface of the dough with egg white and sprinkle with the almonds. Bake for about 45 minutes, until the crust is golden brown and firm.
Cool for at least 20 minutes before cutting, though this tart is also excellent at room temperature or just slightly warm.