Steak 'n Shake Frisco Melt

1 lb ground beef
8 slices sourdough bread
1 tablespoon butter
1/2 onion, sliced thin and caramelized (optional)
8 slices American cheese
4 slices Swiss cheese
Frisco Sauce:
2 Tbsp. Thousand Island
1 Tbsp. Russian dressing

1. If you haven't already prepared the caramelized onions, do so first and set aside. Prepare the Frisco sauce and store in the fridge until ready to use.

2. Roll ground beef into golf ball sized balls. Heat a saute pan to medium high. Add ground beef balls, about 2-4 to a pan, 2 if you have a medium sized pan, or 4 if you have a large pan. The meat should sizzle when you add it, if not, your pan is not hot enough. Let cook for one minute, then flip over and using the back of your spatula, smash the burger flat into a thin patty. After a short time and the ground beef is mostly cooked through, flip once more, and add Swiss to one patty, and one American slice to another. Cover saute pan to help melt the cheese. Place on a paper towel to drain fat.

3. Spread butter on bread, toast in a toaster oven or in a clean saute pan until golden. Spread Frisco sauce to each piece of bread. Add warmed caramelized onions to one slice of bread. Add the patties and serve.