Chicken with Rice

1 chicken breast, halved, skinned and boned
1 cup chicken broth or stock
2 tablespoons chopped onion flour for dredging
1 to 2 tablespoons vegetable oil
1/2 cup uncooked long grain rice Salt and pepper
2 tablespoons butter
4 mushrooms, halved

Salt and pepper chicken and dredge in flour. Saut