Preheat oven to 350° F and lightly spray baking pan with cooking spray.
Cook white rice and wild rice according to package directions (I cook both types of rice together, using the instructions for white rice).
While rice is cooking, place all soups, salt, and pepper in a large mixing bowl and stir together. Add chicken bouillon granules to boiling water and stir until dissolved, then add to soup. Using a whip, mix well.
Add mushrooms and rice to the soup mixture and stir until well blended.
Pour rice mixture into prepad dish. Place chicken pieces on top of the rice mixture and press the chicken down into the mix.
Bake uncovered for 30-40 minutes or until meat juices run clear and the internal temperature at the thickest part reads 165° F.