This salad is best served immediately or while still quite warm. The key is that the dressing and the potatoes need to be warm when the salad is assembled. It suffers when reheated. If you are juggling a couple of dishes, cook the potatoes and keep them in their skins. Make the dressing but don't assemble the salad. Just before serving, heat the potatoes in the microwave, peel them, and toss with the dressing.