In a large skillet over medium heat, brown pork chops on both sides.
Lightly spray the slow cooker with cooking spray. Then place brown and white rice, onion, butter, peas, water chestnuts, and mushrooms in the slow cooker. Pour in water, broth, and Worcestershire sauce. Stir in onion soup mix, season with pepper, and top with pork chops.
Cover, and cook on Low setting for 7 to 9 hours, or on High setting for 4 to 5 hours.
