Cook chicken in large nonstick skillet on medium heat 3 to 4 min. on each side or until breasts are evenly browned on both sides. Transfer chicken to plate, reserving drippings in skillet; cover chicken to keep warm. Add vegetables to skillet; cook and stir 5 min. Add tomatoes; bring to boil. Add chicken; cover and simmer on low heat 8 min. or until chicken is done (165ºF).