Step 1

Heat a cast-iron griddle or large heavy skillet over medium-high until very hot, about 2 minutes, then lightly brush with vegetable oil. Divide ground beef into 4 equal portions (do not form patties).

Step 2

Working in batches if needed, place portions on griddle and smash flat with a spatula to form 4"-diameter patties (craggy edges are your friend). Season liberally with salt and cook, undisturbed, until outer edges are brown, about 2 minutes. Flip patties, season with salt, and place a slice of cheese on top of each patty. Cook until cheese droops and burgers are medium-rare, about 1 minute.

Step 3

Serve patties on rolls with ketchup, mayonnaise, lettuce, and pickles.