If desired, peel potatoes. Cut up potatoes. In a medium covered saucepan cook potatoes in boiling salted water for 20 to 25 minutes or until tender; drain. Transfer potatoes to a large mixing bowl. Beat potatoes with an electric mixer on low speed until mashed. Add sour cream ranch dip, salt, and pepper; beat until well mixed. Fold in the 1 tablespoon snipped chives.
Spoon mixture into four 8-ounce casseroles. Drizzle with melted butter. Bake, uncovered, in a 350 degree F oven for 20 to 25 minutes until heated through. To serve, if desired, garnish with additional snipped chives. Makes 4 side-dish sevings.