2 sheets (about 1 pound) puff pastry (each 9- to 10-inch-square)
1 cup part-skim ricotta cheese
1/2 cup plus 1 teaspoon grated Parmesan cheese
1 large egg, beaten
2 large (about 1 pound) tomatoes, cut in half and sliced 1/4 inch thick
Preheat the oven to 400. Line two baking sheets with parchment paper and place a puff pastry sheet on each piece of parchment. Using a small knife, form a 1-inch “frame” around the edge of the pastry by cutting a row of diagonal marks in the dough. Do not cut all the way through. Use a fork to prick the area inside the frame every 2 or 3 inches. Set aside.
In a small bowl, combine the ricotta, 1/2 cup of Parmesan and the egg. Add pepper and nutmeg to taste and mix thoroughly. Set aside. Spread half of the ricotta mixture over the pastry, keeping it inside the frame. Cover the ricotta with the slices of one tomato, overlapping the slices slightly, like shingles on a roof. Sprinkle half of the remaining Parmesan over the tomatoes. Repeat with the remaining ricotta mixture, tomato slices and Parmesan. Bake until the pastry has puffed and browned, about 20 minutes. Let it rest 5 to 10 minutes before slicing. Serve warm. Serves 8 to 12.