Prepare the Patties: Form the ground beef into 4 equal patties. Season with salt and pepper and cook in a skillet over medium heat until done. Remove and set aside.
Caramelize the Onions: In the same skillet, add 1 tbsp butter and sauté the sliced onions over medium heat until golden brown and tender.
Make the Secret Sauce: In a small bowl, combine mayonnaise, ketchup, Dijon mustard, garlic powder, and paprika. Mix until smooth.
Assemble the Patty Melt: Butter one side of each slice of rye bread. On the unbuttered side, layer Swiss cheese, beef patty, caramelized onions, and more cheese. Top with another slice of bread, buttered side facing out.
Grill the Sandwich: Heat a skillet over medium heat. Cook the sandwiches until the bread is golden brown and the cheese is melted, about 3-4 minutes per side.
Serving and Storage Tips
