Ingredients:

  • 1/2 lb (225 g) ground beef (80/20 blend for flavor and juiciness)
  • 1/2 medium onion, thinly sliced (about 1/2 cup)
  • 2 slices of Swiss cheese (or American cheese)
  • 4 slices of rye bread (or whole wheat for a healthier option)
  • 2 tablespoons unsalted butter (for toasting)
  • 1 teaspoon Worcestershire sauce
  • Salt and pepper to taste

Instructions:

  1. Heat 1 tablespoon of butter in a skillet over medium heat. Add sliced onions; cook until caramelized (about 5-7 minutes), stirring occasionally.
  2. In a separate bowl, season ground beef with Worcestershire sauce, salt, and pepper. Form into one or two patties (about 1/4 lb each). Cook in the same skillet over medium-high heat for 3-4 minutes on each side, until desired doneness.
  3. Place a slice of cheese on top of each cooked patty in the skillet and cover to melt (about 1 minute). On a separate plate, stack the patty, onions, and another cheese slice.
  4. Spread remaining butter on one side of each slice of rye bread. In the skillet, place the buttered side down, and add the assembled patty between two slices. Toast until golden brown (about 2-3 minutes).
  5. Flip with a spatula, toast the other side until golden brown, then serve hot.