Preheat the oven to 400°F. On a floured surface, roll the puff pastry out to a 16-by-10-inch rectangle. Trim uneven edges. Place the pastry on a baking sheet. With a sharp knife, lightly score the dough to form a l-inch border. Using a fork, prick the dough inside the border every 1/2 inch. Bake until golden, rotating the pan once, about 15 minutes.