Step 1

Place potatoes in a Dutch oven; add water to cover. Bring to a boil. Reduce heat; cook, uncovered, until tender, 10-15 minutes. Drain; cool completely.

Step 2

In a small bowl, mix tzatziki sauce, celery, yogurt, green onions, dill, parsley, salt, celery salt, pepper and, if desired, mint. Spoon over potatoes; toss to coat. Refrigerate, covered, until cold.