Spray cold grate of outdoor grill with grilling spray. Prepare grill for medium heat. Place potatoes in large bowl; toss with oil. Add dried dill, garlic powder, 1/4 teaspoon salt and 1/8 teaspoon pepper. Toss to coat evenly. Place potatoes on grill grate and cook 20 minutes or until fork tender, turning several times.
Meanwhile, place beef, mushrooms, Egg Beaters, hummus, Worcestershire sauce, onion powder, mustard and remaining salt and pepper in medium bowl. Combine well. Divide and shape into 4 patties. Place on grill. Cook 5 minutes on each side or to desired doneness. Set aside and keep warm.
When potatoes are done, place burger patties on buns with lettuce and tomato. Serve 4 potato wedges with each sandwich.