A pie is a baked  food that is made from pastry crust with or without a pastry top. The common filling of a pie is either savoury (with meat and/or vegetables) or gravy. Pies often have a round or oval shape. It originated in the United Kingdom.

A pie is cooked beforehand: this is the main idea. It can be cooked days before it is eaten. The crust keeps it in good condition if the pie is kept in a cool place. The pie can be eaten warm or cold.

Ingredients

Pastry 
Pies can be either:
 "filled", where a dish is covered by a pastry crust 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, or
 "two-crust," with the filling completely enclosed in the pastry shell.

Filling 
Pies are baked with a shell or crust, which is usually made of pastry. The filling may be fruit, meat, fish, vegetables, cheeses, creams, chocolate, custards, nuts, or other sweet or savoury ingredients.

Savoury pies 
This list is not meant to be complete.

 Bacon and egg pie
 Butter pie
 Chicken and mushroom pie
 Corned beef pie
 Cottage pie

 Meat and potato pie—made with meat (usually beef) and potatoes
 Pasta pie
 Pork pie

 Quiche
 Scotch pie
 Shepherd's pie (mashed potato crust)
 Stargazy pie
 Steak pie
 Steak and kidney pie

Sweet pies 
This list is not meant to be complete.
Some of these pies are pies in name only. An example is the Boston cream pie, which is a cake.  Many fruit and berry pies are very similar, with the only difference being the fruit used in filling.

Apple pie
Banoffee pie
Banana cream pie
Blackberry pie
Blueberry pie
Boston cream pie
Buko pie
Cheesecake
Cherry pie
Chocolate pie

Chess pie
Cream pie
Custard pie
Dutch apple pie
Key lime pie
Lemon meringue pie
Mince pie
Mississippi Mud pie
Mock apple pie

Peach pie
Pecan pie
Peanut butter pie
Pumpkin pie
Rhubarb pie, Strawberry-rhubarb pie
Shoofly pie—a pie filled with molasses
Strawberry pie
Sweet potato pie

Regional variations 
There are many different kinds of pie. People from different countries often have their own different type of pie.

Great Britain, Australia and New Zealand 
Meat pies with fillings such as steak and cheese, steak and kidney, minced beef or chicken and mushroom are popular in the United Kingdom, Australia and New Zealand as take-away snacks. They are also served with chips as an alternative to fish and chips at British chip shops. A "Wigan kebab" is a pie, put between halves of a flour-covered bap (bun). This is called a barm cake. The combination of pie and mash is associated with London. Shepherd's pie (which does not involve pastry) is a favourite with people in Britain.

Most meat pies are served hot. Pork pies usually have a very high fat content and may be served cold. These meat pies contain beef and gravy in a shortcrust piecase, often with a flaky top. Many bakeries and specialty shops sell gourmet pies. Adelaide (a city in Australia) has the pie floater, where a meat pie is floated in a plate of thick green pea soup.

North America 

Pot pies with a flaky crust and bottom are a popular American dish. They usually have a filling of meat (often beef, chicken or turkey), gravy, and mixed vegetables (potatoes, carrots and peas). Frozen pot pies are often sold in individual serving size.

Fruit pies may be served with a scoop of ice cream, a style known in North America as à la mode. Apple pie is a traditional choice. This combination, and possibly the name as well, is thought to have been popularized in the mid-1890s in the United States.

A tourtière is a meat pie. It was first created in Quebec, Canada. It is usually made with ground pork, veal, or beef.

Rest of world 
Many countries have their own style of pie. For example:
 Spanakopita is a savory pie common in Greece. It has a filling of spinach  and cheese, and spices.
 Buko pie is a traditional Filipino pie with coconut filling.
 Pyrih (or pirog in Russian) is a Ukrainian pie. It may be sweet and contain cottage cheese, or fruits like apple, plums or various berries. Savoury versions may contain meat, fish, mushrooms, cabbage, buckwheat or potato.
 Torta caprese is a traditional Italian chocolate and almond or walnut pie. It is sometimes made with a small amount of liqueur. The name refers to the island of Capri.
 Torta de Santiago is a type of almond pie from the Galicia region in Spain. The filling is mostly ground almonds, eggs and sugar.
 Vlaai is a pie from the Limburg region in the Netherlands. It comes in many different varieties of fruit fillings.
 Zelnik is a traditional Bulgarian pastry. It is made of thin crusts filled with either cheese and eggs, spinach, sorrel, crumbled meat, leeks and rice, or very often in the winter period, brined cabbage.

Pie throwing
Cream filled or topped pies are favourite props for humour, particularly when aimed at people who are too serious. Throwing a pie in a person's face has been a staple of movie comedy since the early days of the movies. It is often associated with clowns in popular culture.

Pranksters have taken to targeting politicians and celebrities with their pies, an act called pieing. Activists sometimes engage in the pieing of political and social targets as well. "Pieing" can result in injury to people and pie throwers can face assault or more serious charges.

References

Other websites 

 The American Pie Council
 History of Pie
 Food Timeline, History Notes: Pie & Pastry 

 
Baked foods