Preheat oven to 400 degrees F. Line a baking sheet with parchment paper and set aside.
On a lightly floured surface, unfold the pastry. Using a 3-inch round cookie cutter, cut out 8 or 9 rounds; place rounds on the prepared baking sheet. Prick the pastry rounds all over with a fork. Sprinkle each with about 1/2 teaspoon Parmesan. Bake rounds for 5 minutes. Remove from oven.
Top each tart with a slice of tomato, basil leaf and mozzarella slice. Bake for 10 minutes or until puffed and golden. Season with salt and pepper, to taste, and serve.