Cook brown rice according to directions on box.
Preheat oven to 350 degrees. Lightly grease an 7×11 inch baking dish.
Meanwhile, season chicken breasts with salt and pepper, place into a large saucepan, and fill with water until just covered.
Bring chicken to a boil, and cook for 15-20 minutes, or until done. Remove chicken from water and cut into bite-size pieces.
In a medium bowl, mix together cream of chicken soup, onion, and salsa.
Layer 1/2 of the rice, 1/2 of the chicken, 1/2 of the soup and salsa mixture, and 1/2 of the cheese in prepared dish. Repeat layers, ending with cheese.
Bake in preheated oven for about 20 minutes, or until bubbly. Enjoy!