Cut into top of cabbage and hollow it out, leaving 3-4 outside leaves intact, reserving the hollowed-out portion. Plunge the hollowed-out head into large amount of boiling water; simmer 5 minutes or until tender-crisp. It must hold its shape. Cool quickly in cold water; invert and drain.Chop reserved cabbage pieces, measure 1 1/2 cups. Stir fry in butter along with green onions until tender. Set aside. Boil and mash potatoes adding milk and seasonings. Stir in the sauteed mixture and parsley.