Preheat oven to 350F.
Heat oil in a large frying pan. Coat chicken pieced evenly in flour. Brown chicken in pan (work in batches if you have to). Set aside.
Dissolve boullion in water.
Add rice, salt, and pepper to a greased baking dish. Sprinkle with onion. Pour mushrooms (and juice) evenly over the rice. Pour boullion over mixture. Place chicken on top, and dot with oleo. Cover and bake for one hour.