Peel potatoes; cut in halves and cook in boiling lightly salted water until tender. Mash slightly.
Place potatoes in large mixer bowl; beat until light and fluffy. Add ¼ c. butter, onion, salt, pepper, parsley, cheese and egg. Whip until well mixed. Cool.
Moisten hands; shape potato mixture into balls, about ¾ c. each. Place on greased baking sheet; fla