Begin by seasoning the burgers with salt and pepper. Heat a saute pan over medium heat until hot. Sear off the burger patties to medium rare, 4 to 5 minutes per side. Transfer the patties to a sheet pan and cool to room temperature.
Assemble the sandwiches with the Swiss cheese and Cheddar slices divided among half of the bread slices and the Caramelized Onions and beef patties divided among the other half of the slices. Combine 1 slice of each kind to create a sandwich.
Heat a 12-inch skillet to medium and melt 4 tablespoons (2 ounces) of the butter into the pan per sandwich. Add in a sandwich and press with a steak weight or another pan to press all the ingredients together and warm and melt the cheese. Flip the sandwich and repeat until golden brown and the cheeses are melting. Repeat with each sandwich until complete.
Cut in half and serve with salad or French fries.
Melt butter in large skillet over medium heat. Add onions and toss to coat with butter. Cover and slowly cook onions, stirring occasionally, for 10 minutes or until a golden Color is reached. Turn heat up to medium high and begin to brown the onions, stirring constantly about 10 more minutes. Season with salt and pepper
Recipe Courtesy of Food Network Kitchens
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.