Form the ground beef into 4 equal patties, slightly larger than the buns. Season both sides with salt and pepper.
Heat a skillet or grill over medium-high heat and add a little oil. Cook the patties for about 4-5 minutes per side, or until they reach your desired product. Add cheese on top of each patty during the last minute of cooking to melt it.
AWhile the patties are cooking, toast the buns in the same skillet or on the grill until golden brown.
Place the cooked patty on the bottom half of the bun. Add tomato slices, onion, lettuce, and any condiments you like. Top with the other half of the bun and serve!