Combine chicken, celery, zucchini, fennel or kohlrabi, green onion, carrot, and apricots, if using, in a large bowl. Stir in Herbed Mustard Mayonnaise till evenly coated. Cover and refrigerate for 4 to 24 hours.
To serve, line six to eight plates with salad greens. Stir chicken mixture; season to taste with salt and pepper and place atop greens. Garnish with orange slices.
Herbed Mustard Mayonnaise
Combine mayonnaise, lemon peel, mustard, lemon juice, fresh dill or tarragon, orange juice concentrate, and pepper. Makes about 3/4 cup.