Heirloom Tomato Tart
1 ⅔ cups sifted all-purpose flour
7 tablespoons cold butter, diced
1 egg, beaten
2 teaspoons water
1 teaspoon salt
1 teaspoon white sugar
Filling:
1 cup pesto, or as needed
1 (8 ounce) ball fresh mozzarella cheese
2 cups heirloom cherry tomatoes, halved
1 pinch coarse sea salt to taste
Pour flour into a bowl and make a well in the center. Add butter, egg, water, salt, and sugar. Work the ingredients together with your fingertips until they resemble bread crumbs. Mix until smooth, pushing with the bottom of your palm to form dough into a ball. Wrap with plastic wrap and refrigerate for about 30 minutes.
Roll dough out into a large round on a floured work surface. Roll up dough over the rolling pin to transfer it to a tart pan with a detachable bottom. Drape dough over the tart pan; press over the bottom and against the edges. Trim the edges. Chill the crust for 30 minutes.
Preheat the oven to 400 degrees F (200 degrees C).
Prick the bottom of the crust with a fork. Line with waxed paper and fill with pie weights or dried beans.
Bake crust in the preheated oven until partially cooked, 8 to 10 minutes. Remove the weights and waxed paper. Continue baking for 5 minutes. Let cool. Leave the oven on.
Spread a thin layer of pesto over the crust. Break mozzarella into pieces over the pesto. Cover with tomatoes.
Return tart to the oven; bake until tomatoes are tender and cheese is melted, about 10 minutes. Season with sea salt before serving.