In 1 or 1 1/2-quart casserole, combine butter and onion; cook uncovered, 4 minutes or until golden brown.
Add livers, coating well.
Stir in remaining ingredients except grapes and .
Cook covered, 6 minutes or until livers are done, stirring occasionally.
Stir in grapes and cook covered, 1 minute to heat through.
Garnish with parsley.