MELT butter in large nonstick skillet on medium-high heat. Add chicken; cover. Cook 4 min. on each side or until done (165°F). Remove from skillet.
ADD water and peppers to skillet; bring to boil. Add stuffing mix; stir just until moistened. Top with chicken.
SPOON salsa over chicken; sprinkle with cheese. Cover. Cook on low heat 5 min. or until heated through.