Caramelized Onion Patty Melt

Instructions

1. Mix salt and pepper in small bowl, set aside. Place 4 slices toasted rye bread on clean cutting board or sheet pan. Shingle 1 slice of Swiss cheese and 1 slice of American cheese on each piece of toast, set aside. 

2. Divide beef into 4 portions and shape into balls. Melt 3 tablespoons of the butter in large cast-iron skillet on medium-high heat. Place beef in hot skillet. Smash beef using a large heavy spatula or burger press to flatten. Sprinkle tops of burger patties with salt and pepper mixture. Cook burger 1 to 2 minutes, or until well browned on bottom. Flip, sprinkling with remaining salt and pepper and cook until browned on both sides and cooked through. 

3. Place burger patties on top of prepared toast and cheese. Spoon 1 tablespoon Caramelized Onion Paste on top of each burger patty. Layer with remaining Swiss cheese and top with remaining toast. 

4. Drain excess oil from skillet and wipe clean with paper towels. Melt remaining 3 tablespoons butter in skillet on medium heat. Transfer assembled patty melts to skillet. Cook on each side until golden brown. Cut in half to serve.