Ingredients:

  • 1 packet (1.3 oz / 37g) French Onion Soup Mix (such as Knorr)
  • 1 lb (450g) ground beef (80/20 blend)
  • 1 tablespoon Worcestershire sauce
  • 1 teaspoon Dijon mustard
  • 4 slices rye bread
  • 4 slices Gruyère cheese
  • 2 tablespoons unsalted butter, softened

Instructions:

  1. In a mixing bowl, combine ground beef, onion soup mix, Worcestershire sauce, and Dijon mustard. Gently mix until just combined.
  2. Divide the mixture into two equal portions and shape each into a patty, slightly larger than the rye bread slices.
  3. Heat a large skillet or griddle over medium heat. Cook the patties for about 5-7 minutes per side, or until cooked through and the internal temperature reaches 160°F (71°C). Let rest for 5 minutes.
  4. While the patties are resting, spread butter evenly on one side of each slice of rye bread.
  5. Place two slices of rye bread (buttered-side down) in the same skillet (wipe out any excess grease if needed). Top each with two slices of Gruyère cheese, then a cooked patty, and finally another two slices of Gruyère. Top with the remaining rye bread slices (buttered-side up).
  6. Cook the patty melts over medium-low heat for 3-4 minutes per side, or until the bread is golden brown and the cheese is melted and gooey. Press down gently with a spatula to ensure even cooking.
  7. Slice the patty melts in half and serve immediately.