A pie is a baked dish of a sweet or savory filling enclosed in pastry: a single-crust pie has the filling topped with pastry, a double-crust pie has it sandwiched between two layers, and other versions include lattice tops and individually-sized hand pies. Pastry-wrapped fillings go back to antiquity in Egypt and Greece, but the flakier, more refined crusts associated with pie today developed later, in medieval Europe. Sweet pies are typically filled with fruit, custard, cream, or nuts; savory pies use meat, seafood, or vegetables, as in chicken pot pie or quiche. The dish carries strong regional identities - apple pie in the United States, meat pies and pasties in Britain, meat pies in Australia and New Zealand, bobotie-style pies in South Africa - and the name is sometimes used loosely for dishes, like shepherd's pie, that use a mashed-potato topping instead of pastry.