1. Coat bell pepper and onion with cooking spray. Place a large nonstick skillet over medium-high heat until hot. Add bell pepper and onion; stir-fry 2 minutes. Remove from skillet, and set aside. Coat both sides of lamb with cooking spray; add lamb to skillet, and cook 3 minutes on each side.
2. Combine wine and remaining 3 ingredients, stirring well. Pour over lamb; bring to a boil over medium-high heat. Cook 6 minutes or to desired degree of doneness, turning lamb once and stirring occasionally.
3. Transfer lamb to a serving platter. Stir vegetables into wine mixture; cook until thoroughly heated, stirring occasionally. Spoon vegetables over lamb.