Spray a skillet with cooking spray and heat over medium. Saute mushrooms for 2-3 minutes. Add spinach, cook for 1 minute more.
Add egg whites to skillet and season with salt. Cook eggs for 2-3 minutes without stirring. Lift up the sides, allowing any uncooked whites to spread out. Place skillet into oven. Broil for 2-3 minutes allowing eggs to completely cook through.
Remove from oven, sprinkle with parmesan cheese. Cut into quarters. Serve each quarter with 1/2 toasted, buttered, bagel and a banana.