INSTRUCTIONS
1
Divide beef into 4 loose balls. Do not pack tightly.
2
Heat a cast-iron skillet over high heat until very hot.
3
Place beef balls on skillet. Immediately smash flat with a metal spatula to 1⁄4-inch thick.
4
Season with salt and pepper. Cook 2 min until a deep crust forms. Flip, add cheese, cook 1–2 min more.
5
Place patty in a lettuce leaf, top with secret sauce and desired toppings. Fold and eat immediately.