Dust a surface with a little flour, then unwrap one piece of pastry. Carefully roll it out until it's large enough to line the base and sides of a 25cm pie dish, skillet pan or cake tin. It is a delicate pastry, if any cracks when rolling, squash them back together and keep going. Lift the pastry over the rolling pin and into the dish - don't worry if it breaks, just patch it up by pushing it into the corners and up the sides and closing any holes.