Preheat oven to 400 degrees F.Spray 9x13 baking dish with cooking spray.Spread entire crescent roll sheet on bottom of pan, trying to close the seams.Next sprinkle with mexican cheese.Then evenly spread the spinach, bell peppers, red onion, and mushrooms.Pour the egg whites on top.Season with salt and pepper.Bake for 15-20 minutes until the crescent rolls are slightly browned and eggs are cooked.