1

Cook potatoes in a large pot of salted boiling water until tender, but still firm and not mushy, about 10-12 minutes. Drain well and cool to room temperature.

2

In a large bowl, mix together the mayonnaises, sour cream, yogurt, vinegar, mustard, parsley, salt and pepper. Add potatoes, eggs, onion, and celery and toss to combine with the dressing. Taste and adjust seasonings as desired. Cover and refrigerate until ready to serve.