Preheat broiler. Beat egg and egg whites together with a fork in a small bowl. Coat a nonstick , oven-proof skillet with cooking spray and heat over medium-high heat. Add shallot, mushrooms and bacon, and cook until mushroom juice evaporates, about 3 to 4 minutes. Remove from pan to a plate and set aside. Place pan back on heat and add egg. Let cook 1 minute, spread vegetable-mixture over egg and place under broiler. Broil until browned and puffed-up, about 4 to 5 minutes. Slide onto a plate and eat while hot.