Cut the lettuce, tomato, and onion into bite-sized pieces.
Season the ground beef for the patty with salt and pepper.
Heat oil in a pan and cook the beef patty on both sides until well done.
Slice the bun in half and lightly toast it in the pan.
Layer sauce, lettuce, tomato, onion, cheese, and the patty on the bun in that order.
Top with the other half of the bun to finish.