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 (as in an apple pie), nuts (pecan pie),
brown sugar (sugar pie) or sweetened vegetables (rhubarb pie). Savoury
pies may be filled with meat (as in a steak pie or a Jamaican patty),
eggs and cheese (quiche) or a mixture of meat and vegetables (pot
pie).
Pies are defined by their crusts. A filled pie (also
single-crust or bottom-crust ), 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. Shortcrust pastry is a typical kind of pastry
used for pie crusts, but many things can be used, including baking
powder biscuits, mashed potatoes, and crumbs. Pies can be a variety
of sizes, ranging from bite-size to ones designed for multiple
servings.