Remove 1 Tbsp. Italian dressing mix from envelope, and set aside; reserve remaining mix for another use.
Cook noodles according to package directions; drain well, and return noodles to pan.
Stir in 2 Tbsp. butter, and toss to coat. Stir in chopped chicken, next 3 ingredients, and 1 Tbsp. dressing mix. Cook mixture over medium-high heat, tossing to coat evenly, 5 minutes or until thoroughly heated. Serve immediately.