In a large stockpot, cover potatoes with water and boil until easily pierced with a fork through the center, about 20 minutes. Drain, cool, and dice into ½” cubes.

In a large glass or ceramic bowl, stir together yoghurt, vinegar, celery, onions, eggs, and mustard. Add cooled potatoes and stir until coated evenly. Season with salt and pepper to taste. Cover and chill for several hours. Garnish with chopped parsley.

Makes 6 to 8 servings.