Whisk the ingredients: In a small bowl, whisk together the mayonnaise, Dijon mustard, apple cider vinegar, sugar, salt, and pepper until smooth and well combined.
Step 3: Assemble the Salad
Combine ingredients: Add the chopped celery, red onion, parsley, and diced hard-boiled eggs to the bowl with the potatoes.
Add the dressing: Pour the prepared dressing over the potato mixture and gently toss until everything is evenly coated.
Step 4: Chill and Serve
Chill the salad: Cover the bowl with plastic wrap and refrigerate the potato salad for at least 1 hour to allow the flavors to meld together.
Serve and enjoy: Once chilled, give the salad a final toss and serve it garnished with additional parsley, if desired.
