I call this flat tart a Bumbleberry Pizza because it’s cooked on a pizza stone and served with cheese and oregano. Sounds like a pizza to me, right?
- 1 cup all-purpose flour (plus more for rolling)
- ½ teaspoon kosher salt
- ½ cup very cold, unsalted butterbutter (cut into ¼‑inch cubes)
- 4 tablespoon ice water
- 8 ounce mixed fresh berries (such as raspberry, blueberry and black berry) by weight
- ¼ cup granulated sugar
- 1 tablespoon corn starch
- 1 tablespoon minced fresh oregano leaves (or to taste)
- 1 large egg yolk (lightly beaten with 1 teaspoon water, as egg wash)
- mascarpone cheese (as needed) at room temperature
- tiny sprigs fresh oregano (as garnish, optional)
In a large bowl, combine the flour with salt. Add the chilled butter cubes and use a pastry cutter or fork to work the butter into the flour, forming a crumbly mixture. Work quickly so the butter stays cold. Drizzle over 3 tablespoons of ice water and mix quickly with a fork, careful not to over-mix. The dough may not come together completely; this is fine. However, if the dough feels especially dry, drizzle over up to 1 additional tablespoon of ice water.
Place the dough in the center of a large sheet of plastic wrap. Pull the edges of the plastic wrap around the dough, pressing the dough into a disk. Seal tightly and refrigerate until chilled, at least 1 hour.
Place the oven racks in the top and bottom positions. Set a pizza stone on the top rack and a rimmed baking sheet on the bottom rack (to capture drizzles). Heat the oven to 400 degrees F.
Sprinkle your work surface generously with flour. Unwrap the dough and give it few gentle kneads to bring the mixture together into a pliable, workable dough. Roll the dough into an 12-inch circle a generous 1/8‑inch thick. Use an 11-inch plate as a template to trim dough into a neat round. Turn up the outer edge of the round of dough to form a one-half-inch rim, then flip the dough over creating a seemless raised lip.
Line a rimless baking sheet with parchment, or alternatively use the underside of a rimmed baking sheet. Carefully transfer the dough round, draped over your rolling pin, to the lined baking sheet. Refrigerate at least 10 minutes.
Meanwhile, combine berries, sugar, cornstarch and minced oregano in a medium bowl; toss to combine. Set aside to macerate about 10 minutes. Toss again to incorporate any undissolved cornstarch.
Spoon the berry mixture and all the juices into the center of the chilled dough. Spread it to the edge of the dough round, leaving the rim uncovered. Brush the exposed rim with egg wash.
Carefully slide the parchment and the tart onto the very hot pizza stone. Bake the pizza until the berries are juicy and bubbling and the crust is golden brown, about 30 minutes. Slide the parchment and tart back onto the rimless baking sheet and transfer to a rack to cool. Cut into wedges and garnish with a dollop of mascarpone and a fresh oregano sprig (if using); serve immediately.