In a large bowl, combine the flour and a pinch of salt. Add cold, diced butter and quickly rub it in with your fingertips until the mixture resembles coarse crumbs. Stir in a little cold water—start with 2-3 tablespoons—and knead gently until the dough comes together. Wrap in plastic wrap and chill for at least 30 minutes

Preheat your oven to 200°C (390°F). Roll out the chilled dough on a lightly floured surface into a rustic, 12-inch (30 cm) circle. Transfer to a parchment-lined baking sheet. Chill again for 10 minutes to firm up the crust

While the crust chills, slice the tomatoes and toss them with minced garlic, chopped herbs, a drizzle of olive oil, salt, pepper, and lemon zest. Let sit for 10 minutes to meld flavors and remove excess moisture. Meanwhile, spread a thin layer of mustard over the chilled crust

Spread a layer of ricotta, dot with dollops of goat cheese, crumbles of Parmesan or Gruyère, and scattered slices of mozzarella over the crust, leaving a 2-inch border. Pile the seasoned tomatoes on top, pressing them gently into the cheeses. Drizzle with pesto if desired

Fold the edges of the dough over the filling, pleating as needed for a rustic look. Brush the exposed crust with beaten egg or egg wash to give it a shiny, golden finish. Bake for about 35-40 minutes, or until the crust is flaky and golden brown

Let cool slightly before slicing. Serve warm or at room temperature, garnished with fresh basil and a drizzle of crème fraîche for an elegant touch.