Toss potatoes with oil, salt and pepper; place in a grill wok or basket. Grill, covered, over medium heat 20-25 minutes or until potatoes are tender, stirring occasionally. Transfer potatoes to a large bowl; cool slightly., In a small bowl, mix dressing ingredients. Add dressing, eggs and celery to potatoes; toss to combine. Refrigerate, covered, 1-2 hours or until cold. If desired, sprinkle with chives.