Fill a large pot with water and bring it to a rolling boil over high heat. Add the peeled and cubed potatoes and cook until they are tender when pierced with a fork, about 15-20 minutes. Drain the potatoes and let them cool slightly.
While the potatoes are cooling, prepare the dressing by whisking together mayonnaise, yellow mustard, and apple cider vinegar in a mixing bowl until smooth. Incorporate chopped dill and season with salt and pepper to taste.
Once the potatoes are warm but manageable to handle, transfer them to a large mixing bowl. Gently fold in the dressing, ensuring each piece is coated evenly. The potatoes should be glossy and coated with the dressing, with no excess liquid pooling.
Adjust seasoning by tasting a small amount and adding more salt and pepper if needed. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes to allow flavors to meld.
Before serving, give the potato salad a gentle stir. Garnish with additional dill if desired, and serve chilled. The finished salad should be creamy, with tender potato chunks evenly coated in bright dressing and topped with fresh herbs.
