Preheat your grill or skillet to medium-high heat.
In a bowl, season the ground beef with salt and pepper.
Divide the beef into 4 equal portions and shape them into patties.
Make a slight indentation in the center of each patty.
Place the patties on the grill and cook for about 4 minutes.
Flip the patties and place a slice of cheese on each.
Cook for another 3-4 minutes until the cheese is melted.
Toast the burger buns on the grill for about 1 minute.
Assemble the burger with the patty, lettuce, tomato, onion, and pickles.
Add ketchup and mustard to taste, then top with the other half of the bun.