A pie is a baked dish which is usually made of a pastry dough casing that contains a filling of various sweet or savoury ingredients. Sweet pies may be filled with fruit, nuts, brown sugar or sweetened vegetables. Savoury pies may be filled with meat, eggs and cheese or a mixture of meat and vegetables.
Pies are defined by their crusts. A filled pie, has pastry lining the baking dish, and the filling is placed on top of the pastry but left open. A top-crust pie has the filling in the bottom of the dish and is covered with a pastry or other covering before baking. A two-crust pie has the filling completely enclosed in the pastry shell.