Hamburger

 A hamburger, or simply a burger, is a dish consisting of fillings—usually a patty of ground meat, typically beef—placed inside a sliced bun or bread roll. 

The patties are often served with cheese, lettuce, tomato, onion, pickles, bacon, or chilis with condiments such as ketchup, mustard, mayonnaise,

 relish or a "special sauce", often a variation of Thousand Island dressing, 

and are frequently placed on sesame seed buns. A hamburger patty topped with cheese is called a cheeseburger.^[1]

 Under some definitions, and in some cultures, a burger is considered a sandwich.