A pie is a bake dish which is usually made of a pastry dough shell that covers or completely contains a filling of fruit, meat, fish, vegetables, cheeses, creams, chocolate, custards, nuts, or other sweet or savoury ingredients. Pies can be either "filled", where a dish is covered by pastry and the filling is placed on top of that, "top-crust," where the filling is placed in a dish and covered with a pastry/potato mash top before baking, or "two-crust," with the filling completely enclosed in the pastry shell.