Probably the most famous sandwich in the world is the American hamburger.
Flattened, and typically round minced meat is placed between slices of bun or roll bread and accompanied by tomatoes, cucumbers, cheese, onions, pickles, lettuce, and bacon. Usually, some mayonnaise, ketchup, mustard, or some sauce is added.
While there are some theories about hamburgers originating from Germany, these popular sandwiches have been widely consumed in the USA and this is where they reached their world fame. Hamburger is considered to be the national dish of the USA, and undeniably it is one of the most popular foods in the world.