Start by washing the red potatoes thoroughly.

Cut the potatoes into halves or quarters for even cooking.

Place them in a large pot, cover with water, and add a pinch of salt.

Boil the potatoes for about 15-20 minutes until tender but not falling apart.

Once cooked, drain the potatoes in a colander and allow them to cool.

In a mixing bowl, combine the mayonnaise, Dijon mustard, salt, and pepper.

Add the chopped red onion, celery, and parsley to the dressing.

Once the potatoes have cooled, gently fold them into the dressing and vegetable mix.

Cover the salad and refrigerate for at least one hour to allow flavors to meld.