"The secret: cooking the burgers IN mustard...."
vegetable oil
butter
large onion, chopped
Kosher salt
Freshly ground black pepper
apple cider vinegar
mayonnaise
honey mustard
barbecue sauce
lemon juice
ground beef
Kosher salt
Freshly ground black pepper
slices American cheese
yellow mustard
potato buns, toasted
Iceberg lettuce
tomato, sliced