Creating the perfect Patty Melts with Secret Sauce is easier than you might think. Just follow these steps:

1. Make the Secret Sauce: In a small bowl, combine the mayonnaise, ketchup, mustard, Worcestershire sauce, garlic powder, and cayenne pepper. Mix well and set aside.
2. Prepare the Onions: In a skillet over medium heat, melt 1 tablespoon of butter. Add the sliced onions and season with salt and pepper. Cook until the onions are caramelized, about 10 minutes, stirring occasionally.
3. Form the Patties: While the onions are cooking, divide the ground beef into four equal portions. Form each portion into a patty, making them slightly larger than the bread to account for shrinkage during cooking. Season both sides with salt and pepper.
4. Cook the Patties: In another skillet over medium-high heat, add a little oil and cook the patties for 4-5 minutes on each side or until they reach your desired doneness. Place a slice of Swiss cheese on each patty during the last minute of cooking to melt.
5. Assemble the Melt: Butter one side of each slice of bread. Spread the secret sauce on the unbuttered side of two slices. Place a cheesy patty on each slice, then add a generous portion of caramelized onions. Top with the other slices of bread, buttered side facing out.
6. Grill the Sandwiches: Return the sandwiches to the skillet over medium heat. Cook for about 4-5 minutes on each side until the bread is golden brown and crispy, and the cheese is fully melted.
7. Serve: Once cooked, let the sandwiches sit for a minute before slicing in half to serve.

These steps will guide you to create the most delicious Patty Melts with Secret Sauce, guaranteed to impress anyone at your dining table.