01 -
85/15 ground beef (12 ounces).
02 -
Salt (1/2 teaspoon).
03 -
Pepper (1/2 teaspoon).
04 -
Worcestershire sauce (1 teaspoon).
05 -
Olive oil (2 tablespoons).
06 -
Large onions, thinly sliced (2).
07 -
Mayonnaise (1/4 cup).
08 -
Ketchup (2 tablespoons).
09 -
Dijon mustard (1 tablespoon).
10 -
Pickle juice (1 teaspoon).
11 -
Paprika (1/4 teaspoon).
12 -
Garlic powder (1/4 teaspoon).
13 -
Swiss cheese slices (4).
14 -
Cheddar cheese slices (4).
15 -
Rye bread (8 slices).
16 -
Unsalted butter (3 tablespoons).