Smash burgers: divide ground beef 18% fat or above in 110g balls and salt them, heat a skillet or griddle over medium high heat and smash a ball, flip after a minute, add cheese and cover and cook for another minute.
Bacon: Add a pan to the stove and add the bacon. Then turn on at medium to low heat. Fry till crisp and golden. Set aside on kitchen towel.
Slice lettuce and onions finely. Slice thin slices of tomato and assemble your burger.