These thick, juicy burgers will be a hit at any cookout. Serve with buns and your favorite burger fixings.
1. Whisk together Liquid Aminos, wine, 1 Tbs. oil from tomatoes, mustard, pepper, and 1/2 cup water in bowl. Pour over mushrooms, and let marinate 10 minutes. Drain.
2. Heat grill or grill pan over medium heat. Grill mushrooms bottom side down 4 minutes; grill onion rings 5 minutes. Transfer mushrooms to platter bottom side up. Fill each of 4 mushrooms with 1 onion ring, 1 tomato, and 1 oz. cheese. Top with remaining 4 mushrooms. Secure with toothpicks. Grill burgers 10 minutes more, turning once, or until cooked through. Remove toothpicks.