Pizza

The word pizza comes from the Italian word pizza meaning "a mess". Italian plural: pizze.

A pizza is an oven-baked, flat, usually circular bread covered with tomato sauce and cheese with optional toppings and baked. The cheese is usually mozzarella. Various other foodstuffs can be added as toppings, most typically ground meats and sausages, such as salami, pepperoni, ham and bacon, fruits such as pineapple and olives, vegetable-like fruits such as peppers and vegetables such as onions, and fungi such as mushrooms. The crust is traditionally plain. Pizza can be eaten either hot or cold.

The earliest pizzeria opened in 1830 at Via Port'Alba 18 in Naples, Italy and is still in business today. Pizza was still considered "poor man's food" in 1889 when Rafaele Esposito, the most famous pizzaiolo of Naples, was summoned before King Umberto I and Queen Margherita to prepare the local speciality. It is said that he made two traditional ones and additionally created one in the colours of the Italian flag with red tomato sauce, white mozzarella cheese, and green basil leaves. The Queen was delighted and "pizza Margherita" was born.

Source: Wikipedia

Check that you understand what these words mean in this document
Topping: something that we put on top of other food to give extra flavour and to make them look attractive.
To summon: to order someone to come.