Combine potatoes, cucumber, onion, and egg whites. ... and combine with sour cream, mayonnaise, vinegar, mustard and seasonings. Blend ... several hours. Serves 8.
Place potatoes in bowl; pour ... egg yolks. Add sour cream, mayonnaise, vinegar and mustard; mix well. Pour ... 20 minutes. Add cucumbers just before serving. Garnish with parsley.