Steps
1. Preheat a skillet or grill over medium-high heat.
2. Season the beef patty with salt and pepper on both sides.
3. Cook the patty for about 3-4 minutes on one side, then flip it.
4. Place the slice of cheddar cheese on top of the patty and cook for another 3-4 minutes, until the cheese is melted.
5. While the patty is cooking, lightly toast the hamburger bun in another pan or on the grill.
6. Assemble the burger by spreading mayonnaise on the bottom bun, followed by the lettuce, the cooked patty with melted cheese, tomato slices, onion, and any additional condiments you like.
7. Top with the other half of the bun and enjoy!