01 -
Give it about a minute to rest. Slice at an angle and enjoy with sauce on the side or drizzled over the top.
02 -
Spread butter on one side of each bread. Stack bread (buttered side out), cheddar, onion, beef patty, Swiss, and another bread (buttered side out). Cook in a skillet 2-3 minutes per side until the bread is golden and cheese is gooey.
03 -
Stir the mayonnaise, ketchup, pickle relish, and Worcestershire sauce in a bowl. Keep it handy.
04 -
On medium heat, melt 1 tablespoon of butter in a big pan. Stir the onions occasionally until they turn golden and soft after about 15-20 minutes. Put them aside.
05 -
Shape the beef into 4 thin patties. Sprinkle both sides with salt and pepper. Use the same skillet on medium-high heat for 3-4 minutes each side until cooked through. Set aside.