Combine cabbage, pineapple, water chestnuts, parsley, and onion. Cover and chill.
For dressing, combine mayonnaise, mustard, and gingerroot. Cover and chill. Spoon dressing over the cabbage mixture; toss to coat.
PER SERVING: 57 cal., 1g pro., 9g carbo., 2g fat, 0mg chol., 80mg sodium.