Ingredients
Method
Preparation
- Heat a skillet over medium heat. Melt 1 tablespoon of butter and add the sliced onions. Cook until caramelized, about 10-15 minutes. Remove from the skillet and set aside.
- In the same skillet, increase the heat to medium-high. Divide the ground beef into two patties and season with salt and pepper. Cook for about 4-5 minutes on each side or until desired doneness is reached.
- Prepare the secret sauce by mixing mayonnaise, ketchup, and Dijon mustard in a bowl.
Assembly and Cooking
- Spread some secret sauce on one side of each slice of rye bread.
- Place a beef patty on two slices, top with Swiss cheese and caramelized onions, and then cover with the other two slices of bread, sauce side down.
- Add the remaining tablespoon of butter to the skillet. Grill the sandwiches over medium heat until the bread is golden brown and the cheese is melted, about 3-4 minutes per side.
- Remove from skillet, slice in half, and serve warm.
Notes
Serve with extra secret sauce on the side for dipping. Pairs well with pickles, potato chips, or a fresh side salad. For heartier meal, serve with crispy fries. Wrap leftovers in plastic wrap or foil and store in the refrigerator, best eaten within a couple of days.
