Pizza

In its basic form, a pizza (alternatively pizza pie) is an oven-baked flat, usually circular bread covered with various toppings and baked. The usual toppings are cheese and a tomato-based sauce. The cheese is usually mozzarella or its commercial substitute, pizza cheese. Various other foodstuffs can be added to this design, most typically processed meats such as salami and pepperoni, ham and also vegetables such as sweet bell-peppers (of the capsicum family), and mushrooms. The crust can be flavored with garlic or sessame. A Chicago pizza contains the thick toppings between two layers of crust.

Pizza has become an international food since the toppings can be extensively varied to meet local variations in taste. These pizzas consist of the same basic design, but include an exceptionally diverse choice of ingredients, such as egg, pineapple, eggplant, lamb, couscous, chicken, fish and shell-fish, meats done in ethnic styles such as Morroccan lamb and non-traditional spices such as curry and Thai sweet chili. A "white pizza" uses no tomato sauce, often substituting pesto sauce. Pizzas with "non-traditional ingredients" is known in the United States as a "gourmet pizza".

The pizza originated in Naples, but it became a popular meal item in America in the early 20th century. Since then it has spread throughout the world. Several major corporations are chiefly engaged in the commercial production of pizza, notably Pizza Hut (owned by Tricom Global Restaurants), Domino's Pizza, and Papa John's Pizza. These pizza chains often coexist with locally owned and operated pizza chains. Because pizza's can be made quickly and is easily transported, most pizza restaurants in the United States offer call-in delivery services. The lack of such delivery services at the time in England was the focus of an extended passage in Dirk Gently's Holistic Detective Agency authored by Douglas Adams.

In the United States, pizza is also found in supermarkets as a frozen food. Considerable amounts of food technology has gone into the creation of palatable frozen pizzas. The main challenges include preventing the sauce from combined with the dough, and to produce a crust can be frozen and reheated without becoming rigid.

Pizza may be baked with thin bread bottom (Italian style) or with thicker bread (pan pizza). In restaurants it can baked in a conveyor belt oven or in the case of more expensive restaurants, a brick oven.