Instructions

  1. In a bowl, combine beef, onion, garlic salt and pepper.
  2. Mix well.
  3. Shape into 6 patties 3/4 inch thick.
  4. In a small bowl, combine the cheese, mushrooms, bacon and mayo.
  5. Refrigerate.
  6. Grill burgers turning only once.
  7. During the last 3 minutes, spoon 1/4 cup of the cheese mixture onto each burger.