Marinate mushrooms for 30 minutes in Worcestershire sauce (reserving 1 tablespoon). Combine mayonnaise, remaining Worcestershire, mustard, parsley, and 1/2 teaspoon pepper.
Remove mushrooms from marinade (discard unused marinade) and grill; slice mushrooms. Form ground chuck into 4 patties. Season with salt and pepper and grill. Just before desired doneness is reached (recommended 160°F internal temperature), top burgers with cheese and grill until cheese melts.
Generously spread bun with flavored mayonnaise, top with burgers, red onion, mushrooms and bacon. Note: Make mini burgers for children, or to serve as appetizers. Serve 2 oz. patties on small rolls.
Nutritional Information per Serving: 732 Calories; 50g Fat; 16g Saturated Fat; 158mg Cholesterol; 28g Carbohydrate; 1g Dietary Fiber; 50g Protein; 988mg Sodium; 38 percent daily value Iron (based on 2,000 calorie diet).
Recipes provided by the Certified Angus Beef brand. For more information, visit www.certifiedangusbeef.com or follow the brand on Twitter at www.twitter.com/CertAngusBeef and become a fan of “Certified Angus Beef brand” on Facebook.