Begin by placing the whole, unpeeled Yukon Gold potatoes in a large pot and cover them with water. Bring to a rapid boil then reduce to a simmer for 10-15 minutes, or until fork-tender. Drain and let steam covered for 5-10 minutes.

Once cooled slightly, carefully peel the potatoes if you prefer a smoother texture. Cut into 1-inch chunks for even mixing.

In a large mixing bowl, mash the hard-boiled egg yolks until smooth. Add mayonnaise, buttermilk, yellow mustard, and a splash of pickle juice, stirring to combine. Season with salt and pepper.

Pour the dressing over warm potato chunks in a large bowl. Gently fold in chopped egg whites, celery, red onion, and dill pickles until well coated.

Transfer to a covered container and refrigerate for at least 2 hours to chill, allowing flavors to meld before serving.