• Step 1: Place the cubed potatoes in a large pot and cover with cold water. Bring to a boil over high heat, then reduce heat and simmer for 12-15 minutes, or until the potatoes are tender when pierced with a fork. Drain the potatoes and let cool completely.
• Step 2: In a large bowl, whisk together the sour cream, mayonnaise, vinegar, Dijon mustard, salt, and black pepper until well combined.
• Step 3: Add the cooled potatoes, diced celery, diced onion, and chopped parsley to the sour cream dressing. Gently fold everything together until the potatoes are evenly coated.
• Step 4: Cover and refrigerate the potato salad for at least 30 minutes to allow the flavors to meld. Serve chilled or at room temperature.