Boil and Chop Potatoes: Place the whole, unpeeled potatoes in a large pot of water. Bring the water to a boil, then lower the heat and simmer for 10 to 15 minutes, until the potatoes are fork tender. Drain the water completely from the pot and then cover the pot with a lid to allow the potatoes to steam for 5-10 minutes. Peel potatoes, if desired, and cut them into 1/2 inch chunks.

Make Dressing: Separate egg yolks from the whites of the hard boiled eggs and place the yolks in a bowl. Mash the yolks with a fork and then stir in the mayonnaise, buttermilk, mustard, a splash of pickle juice, and salt and pepper, to taste.

Assemble: Pour the dressing over the warm potatoes. Chop the egg whites and add them to the potatoes along with the celery, onion, and pickles. Stir well, cover, and refrigerate for a few hours to allow the flavors to blend.