Spray 9x13 pan with cooking spray. Add Chicken breasts and season with salt and pepper
Pour uncooked rice over chicken. Sprinkle with onion soup mix.
Combine mushroom soup and 1 1/2 cups of water. Pour over chicken.
Cover and bake 1 hour and 15 minutes or until rice is tender.
Notes
It should be noted that this recipe always takes the original poster 1 hour and 15 mintues but depending on your own variables, this recipe can take an extra 25 minutes.