Step 1

Place the potatoes in a large pot of salted water over high heat. Bring the water to a boil, and reduce the heat to medium. Let it simmer for 10 to 15 minutes, or until there’s no resistance from the potatoes when poked with a fork or skewer.

Step 2

Drain the potatoes in a colander and place the colander over the pot. Cover the pot with a dry kitchen towel and let the potatoes steam for 15 to 20 minutes.

Step 3

Meanwhile, whisk together mayonnaise, buttermilk, Dijon mustard, whole grain mustard, dill, 1 teaspoon salt, and 1 teaspoon pepper until well-combined.

Step 4

Once cool enough to handle, peel the potatoes and slice them into halves or quarters, depending on their size.

Step 5

Place the potatoes in a large bowl. Pour the dressing and toss to coat. Add the celery, onion, 2 teaspoons of salt, and 1 teaspoon of pepper, and toss again.

Step 6

Cover the bowl and refrigerate for 30 minutes to a few hours for the flavors to marry. Serve chilled or at room temperature. Enjoy!