01 - Divide ground beef into 4 equal portions and loosely roll into balls without packing tightly.
02 - Heat a large cast-iron skillet or griddle over high heat until very hot.
03 - Place beef balls on hot skillet. Using a heavy spatula or burger press, smash each ball down firmly until about ½-inch thick.
04 - Season immediately with salt and pepper. Cook without moving for 2–3 minutes until edges are deeply browned and crispy.
05 - Flip burgers, top each patty with a slice of cheese, and cook 1–2 minutes more until cheese melts and burgers are cooked through.
06 - While burgers cook, melt butter in a separate skillet or on the griddle. Toast buns, cut side down, until golden brown.
07 - Spread burger sauce on bottom buns, add lettuce, tomato, and onion. Top with smash patties, pickles if desired, and cover with top bun.
08 - Serve immediately.