MELT butter in large nonstick skillet on medium-high heat. Add chicken; cook 6 to 7 min. on each side or until done (165ºF). Remove from skillet.
ADD water and vegetables to skillet; bring to boil. Add stuffing mix; stir just until moistened. Top with chicken, gravy and cheese; cover.
COOK on low heat 5 min. or until gravy is heated through and cheese is melted.