Ingredients
Method
- Whisk together mayo, ketchup, relish, vinegar, sugar, salt, and pepper in a bowl. Refrigerate.
- Slice tomato and onion into thin rounds, shred lettuce, and set aside.
- Divide beef into 8 equal balls, about 2 oz each, without overworking.
- Heat a large skillet or griddle over medium-high. Place beef balls down in batches, smash into thin rounds with a spatula and parchment, season with salt and pepper. Cook 2 minutes, then squirt a thin line of mustard on top of each patty. Flip, cook 1 minute, top with cheese, and cook 30 seconds more until melted.
- Toast buns cut-side down on the warm griddle for about 1 minute.
- Spread sauce on bottom buns, layer lettuce, tomato, onion, two patties, and top bun. Serve immediately.
Notes
If you don’t have a griddle, a large cast-iron skillet works perfectly. The spread tastes better after resting at least 15 minutes, so make it first. Wrap assembled burgers in wax paper to steam for a minute if you want that soft, melty drive-thru texture.
