Boil the peeled potatoes in a large pot with salted water until they are just tender.
Drain and let them cool down until they are comfortable to touch.
While the potatoes are cooling, prepare the dressing by combining mayonnaise, sour cream, Dijon mustard, and apple cider vinegar in a large bowl.
Mix until smooth.
Cut the cooled potatoes into bite-sized pieces and add them to the dressing.
Stir gently to coat the potatoes without smashing them.
Add the finely chopped red onion, dill, and parsley.
Mix these ingredients carefully to distribute them evenly throughout the salad.
Season the salad with salt and pepper according to your taste preference.
Taste and adjust if necessary.