GRILL DIRECTIONS: Heat grill. Cut 16x12-inch sheet of heavy-duty foil; spray foil with nonstick cooking spray. In medium bowl, combine all burger ingredients; mix well. Shape mixture into 4 patties, 1/2 inch thick.
In another medium bowl, combine zucchini, mushrooms and salad dressing; toss to coat.
When ready to grill, place sprayed foil on grill. Spoon vegetables onto sprayed foil. Place patties next to foil on gas grill over medium heat or on charcoal grill 4 to 6 inches from medium coals. Cook 11 to 13 minutes or until vegetables are tender and burgers are thoroughly cooked, stirring vegetables and turning burgers once during cooking.
Meanwhile, toast or grill bread slices; place on individual serving plates.
Top each burger on grill with tomato slices and cheese. When cheese is melted, place each topped burger on bread slice. Top with vegetables.