The Patty Melt

• 6 tablespoons butter, at room temperature
• 2 large onions, thinly sliced
• 8 slices rye bread
• 1 12 lbs ground chuck
• 8 slices swiss cheese

1. Melt 3 tablespoons butter in a large skillet (cast-iron is preferred) over medium heat.
2. Add in onions; cook/stir until caramelized, about 20 minutes; remove onions from pan and set aside.
3. Lay rye bread on waxed paper on a baking sheet.
4. Butter each slice of bread on the top side, dividing 1 tablespoon of the remaining butter among 8 slices; flip bread over and butter the other sides of the 8 slices, dividing 1 tablespoon of butter among them.
5. Reheat skillet that cooked the onions over medium heat.
6. Toast bread on both sides in the skillet until the bread is light gold, about 1 minute per side; set aside.
7. Divide beef into 4 even amounts; shape each into an oval patty about 1/2 inch thick.
8. Season both sides with salt and pepper.
9. Add to the same skillet you have been using over med-high heat; cook patties 2 1/2 to 3 minutes per side for medium-rare doneness; remove from skillet and put sandwiches together.
10. Lay out 4 slices of toasted bread; top with 1/4 of the onion mixture, then a slice of cheese, a beef patty, and a second slice of cheese; top with remaining 4 toast slices.
11. Melt in remaining 1 tablespoons butter in skillet; toast sandwiches on both sides, about 1 minute per side, until bread is toasty brown and cheese is melted.
12. Serve immediately.

butter, onions, rye bread, ground chuck, swiss cheese

Taken from www.food.com/recipe/the-patty-melt-223838 (may not work)