01 -
Divide beef into 4 mounds, and evenly place on a 12-by-14-inch piece of plastic wrap. Place another piece of plastic on top. Roll into 5 1/2-inch patties, about 1/3 inch thick, with a rolling pin.
02 -
Heat a griddle or 2 large cast-iron skillets over medium-high. Season both sides of patties with salt and pepper. Cook patties, pressing with a spatula, for 3 minutes. Reduce heat to medium, flip, and top with cheese. Cook for an additional 2 minutes.
03 -
Butter the cut sides of rolls and toast on the griddle until edges just start to brown, about 1 minute.
04 -
Sandwich burgers in rolls with onion, pickle, lettuce, and mustard.