1 can (10-3/4 ounces) condensed cream of celery soup, undiluted
1/4 cup butter
1/4 cup minced chives, divided
Place potatoes in a saucepan; cover with water. Cover and bring to a boil; cook until just tender, about 5 minutes. Drain well. In a bowl; combine 3 cups cheese, sour cream, soup, butter and 3 tablespoons chives. Add potatoes; stir gently until potatoes are coated.
Transfer to a greased 1-1/2-qt. baking dish. Cover and bake at 350° for 35-40 minutes or until heated through. Sprinkle with remaining cheese; bake 2-3 minutes longer or until cheese is melted. Sprinkle with remaining chives.