HEAT large skillet sprayed with cooking spray on medium-high heat. Add chicken; cover skillet with lid. Cook 5 to 7 min. on each side or until chicken is cooked through (165ºF). Remove chicken from skillet; cover to keep warm.
ADD water, soup, ham and mustard to skillet; cover. Cook 6 min. or until heated through, stirring occasionally.
RETURN chicken to skillet. Cook and stir 1 min. or until chicken is coated and heated through. Sprinkle with cheese.