1. Heat a large skillet coated with cooking spray over medium-high heat. Cook turkey and onion for 5 minutes or until onion is soft, stirring frequently.
2. Stir in tomatoes and its juices, corn, beans, tomato sauce and chili powder. Bring to a boil, reduce heat, cover and simmer 12-15 minutes or until slightly thickened.
3. Serve with lime wedges and top with sour cream and cilantro, if desired. Salt and pepper to taste.