Wash potatoes and place, unpeeled, in a large pot. Fill pot so that the water just covers the potatoes, salt the water, and bring to a boil. Reduce to a simmer and cook until the potatoes can be easily pierced with a fork, about 20 minutes or so.

Drain and place in the refrigerator to cool completely.

Cut cooled potatoes into 1" to 1 ½" chunks.

In a large bowl, whisk together mayonnaise, lemon zest and juice, chives, and dijon mustard. Add salt and pepper to taste. Add potatoes to mixture and toss to combine.

Refrigerate for at least 1 hour before serving.