Wash the red potatoes thoroughly under cold water.
Place the potatoes in a large pot and cover them with water.
Add a pinch of salt to the water and bring it to a boil.
Cook the potatoes for about 15-20 minutes or until fork-tender.
Drain the potatoes and allow them to cool slightly.
Cut the cooled potatoes into bite-sized pieces.
In a separate bowl, combine mayonnaise, Dijon mustard, and apple cider vinegar.
Stir in the chopped green onions and parsley.
Fold the potatoes into the dressing, ensuring all pieces are coated.
Season with salt and pepper to taste, and chill before serving.