• 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 10-15 minutes, or until the potatoes are tender when pierced with a fork. Drain the potatoes and let them cool completely.
• Step 2: In a large mixing bowl, combine the mayonnaise, Dijon mustard, white vinegar, salt, and black pepper. Whisk until well blended.
• Step 3: Add the cooled potatoes, diced celery, diced red onion, chopped parsley, and chopped dill (if using) to the mayonnaise mixture. Gently stir to coat the potatoes and evenly distribute the ingredients.
• Step 4: Cover the potato salad and refrigerate for at least 2 hours, or up to 3 days, to allow the flavors to meld.
• Step 5: Serve chilled or at room temperature, garnished with additional fresh parsley or dill, if desired.