Divide ground beef into loose balls, about 2 to 3 ounces each
Heat a cast-iron skillet or griddle over high heat until very hot
Lightly oil the cooking surface
Place a beef ball on the hot surface
Smash it flat immediately with a heavy spatula or burger press
Season the patty with salt and pepper
Cook until the edges are browned and crispy, about 1 to 2 minutes
Flip the patty once
Add cheese on top if desired
Cook the second side for about 30 to 60 seconds
Toast the burger bun on the hot surface
Assemble with bun, patty, and desired toppings and sauce