Ingredients:

  • 1 large yellow onion, thinly sliced
  • 1 tablespoon olive oil
  • 1 tablespoon unsalted butter
  • 1/4 teaspoon salt
  • 1/4 teaspoon black pepper
  • 1 teaspoon brown sugar
  • 1 tablespoon balsamic vinegar
  • 1 pound ground beef (80/20 blend recommended)
  • 1 teaspoon Worcestershire sauce
  • 1/2 teaspoon garlic powder
  • Salt and pepper to taste
  • 4 slices rye bread
  • 4 slices Swiss cheese
  • 2 tablespoons butter, softened
  • 1/4 cup mayonnaise
  • 1 tablespoon ketchup
  • 1 teaspoon Dijon mustard

Instructions:

  1. Sauté onions in olive oil and butter over medium-low heat, stirring occasionally, until softened and golden brown (about 20-25 minutes). Add brown sugar and balsamic vinegar in the last few minutes.
  2. Gently mix ground beef with Worcestershire sauce, garlic powder, salt, and pepper. Form into two equal-sized patties, slightly larger than the bread slices.
  3. Whisk together mayonnaise, ketchup, and Dijon mustard in a small bowl.
  4. Cook the patties in the same skillet (or a separate one) over medium-high heat until cooked through and browned on both sides (about 4-5 minutes per side). Use a meat thermometer to ensure internal temperature reaches 165°F (74°C).
  5. Spread softened butter on one side of each slice of rye bread. Place two slices of bread (butter-side down) in the skillet. Top each with a slice of Swiss cheese, a cooked patty, caramelized onions, special sauce, and another slice of Swiss cheese. Top with the remaining bread slices (butter-side up).
  6. Cook the patty melts over medium heat, pressing down gently with a spatula, until golden brown and the cheese is melted (about 3-4 minutes per side).
  7. Cut in half and serve hot.