Spray a slow cooker container with butter-flavored cooking spray. In prepared container combine chicken soup, dry onion soup mix, water, and uncooked rice. Stir in chicken, mushrooms and black pepper. Cover and cook on LOW for 6-8 hours. Gently stir just before serving. Per serving: 174 Cal, 2g Fat, 20g Pro, 19g Carb, 467mg Sod, 17mg Calc, 1g Fib Healthy Exchanges: 2 Protein, 1 Bread, 1/3 Vegetable, 1/4 Slider, 10 Opt. Cal. Diabetic Exchanges: 2 Meat, 1 Starch 3 WW points