Preheat your grill or cast-iron skillet over medium-high heat.

Divide ground beef into four equal portions (about 4 oz each) and roll into loose balls.

Season each ball generously with salt and pepper.

Place a beef ball on the hot surface and smash down to about half an inch thick using a heavy spatula. Repeat for remaining balls.

Cook for about 2 minutes until edges are crispy, then top each patty with a slice of cheese.

Assemble on toasted buns with lettuce, tomato, onion, and any additional toppings you prefer.