1. Spray large skillet with cooking spray; heat over medium-high heat. Add bell peppers and onion; cook 7 minutes or until tender, stirring occasionally. Remove from skillet; set aside.
2. Add chicken to skillet. Sprinkle with chili powder and cumin. Cook 4 minutes or until no longer pink, stirring occasionally.
3. Return peppers and onion to skillet; add drained tomatoes. Cook 2 minutes more or until hot. Divide chicken mixture evenly between tortillas.