Whisk the flour and salt together in a mixing bowl. Cut in the cold, cubed butter with your fingertips until the mixture looks like coarse sand with some pea-sized pieces left.

Mix the vinegar into the ice water, then add it to the flour a tablespoon at a time, tossing gently, until the dough just holds together when pressed.

Shape the dough into a disk, wrap it, and chill for 30 minutes.

Slice the tomatoes about 6 mm / 1/4-inch thick and lay them on paper towels. Sprinkle with 1/2 tsp salt and let them sit for 15 to 20 minutes to draw out excess water, then pat dry.

Heat the oven to 200C / 400F and line a 33 x 46 cm / 13 x 18-inch sheet pan with parchment.

Stir the ricotta, parmesan, garlic, half the basil, and black pepper together in a bowl until combined.

Roll the chilled dough between two sheets of parchment into a 35 cm / 14-inch round, then transfer it to the sheet pan.

Spread the ricotta mixture over the dough, leaving a 5 cm / 2-inch border around the edge.

Arrange the drained tomato slices over the ricotta and drizzle with the olive oil.

Fold the dough border up and over the filling, pleating as you go around the edge.

Brush the crust with the beaten egg and sprinkle with flaky salt.

Bake for 40 to 45 minutes, until the crust is deep golden brown and the tomato edges are caramelized.

Cool on the pan for 10 minutes, then scatter the remaining basil over the top and slice into 6 wedges.