Divide ground beef into 4 equal portions and shape into thin patties, slightly larger than the buns. Season both sides with salt and pepper.
Heat a griddle or large skillet over medium-high heat. Cook patties for 3-4 minutes per side until browned and cooked through.
In the last minute of cooking, top each patty with a slice of cheese and cover to melt.
Toast buns on the griddle until lightly golden.
Assemble burgers: spread mayonnaise on bottom bun, add lettuce, tomato, onion, pickles, then two cheese-topped patties. Add ketchup and mustard on top bun. Close burger.
Serve immediately with optional extra toppings.
Tips
For best results, use freshly ground beef and handle gently to avoid tough patties.
Customize with your favorite toppings like bacon, jalapeños, or sautéed mushrooms.
Leftover patties can be refrigerated for up to 3 days.