Tomato and Onion Tart
- 3 ripe but firm tomatoes, 8 to 10 oz. total, cut
into slices 1/4 inch thick
- 1 cup all-purpose flour, frozen for 1 hour
- 1/3 cup cake flour, frozen for 1 hour
- 1/4 tsp. salt
- 12 Tbs. (1 1/2 sticks) unsalted butter, cut into
pieces, frozen for 1 hour
- 2 tsp. fresh lemon juice, chilled
- 1/4 cup ice water
- 1 cup shredded mozzarella cheese
- 1/2 cup freshly grated Parmigiano-Reggiano
- 1 1/2 Tbs. chopped fresh oregano
- 1/4 cup thinly sliced yellow onion, separated into
In the bowl of a food processor fitted with the metal blade, combine both flours, the salt and butter and pulse until the mixture resembles pea-size crumbs. Transfer to a bowl. In a small cup, combine the lemon juice and ice water and add to the bowl. Using a fork, mix until the dough almost holds together.
Turn the dough out onto a lightly floured work surface and press together to form a rough rectangle shape. Large chunks of butter will be visible. Roll out the dough into a rectangle about 8 by 12 inches and 1/2 inch thick. Fold in the 8-inch sides to meet in the center. Then fold in half to make a rough square forming 4 layers. This is your first turn.
Turn the dough a quarter of a turn and roll out again into a rectangle 8 by 12 inches and 1/2 inch thick. Repeat the folding. This is your second turn. Again make a quarter turn and roll out into the same-sized rectangle. Now fold into thirds as you would a business letter. Cover with plastic wrap and refrigerate for 1 hour.
Position a rack in the upper third of an oven and preheat to 400ºF.
On a lightly floured work surface roll out the dough into a 12-inch round. Trim the edges so that they are even, and then crimp to form sides 1/2 inch thick. Transfer to an ungreased baking sheet and sprinkle evenly with the mozzarella, 1/4 cup of the Parmigiano-Reggiano and the oregano. Arrange the tomato slices in concentric circles, overlapping slightly, on the cheese. Scatter the onion rings and then the remaining 1/4 cup Parmigiano-Reggiano over the tomatoes. Bake until the crust is golden and the top is crispy, 25 to 35 minutes. Serve hot.