Potato Salad with Buttermilk Dressing

Directions:

Whisk first 6 ingredients in medium bowl until blended. Season to taste with salt and pepper. Set dressing aside. Cook potatoes in large pot of boiling water until just tender, about 5 minutes. Using 4 to 5 inch diameter strainer, transfer potatoes to colander; rinse under cold water to cool. Drain. Transfer to large bowl. Return water in pot to boil. Cook carrots in same pot of boiling water until crisp-tender, about 2 minutes. Add celery and cook one minuet longer. Drain. Rinse carrots and celery under cold water to cool. Drain well. Mix into potatoes. Add enough dressing to vegetables to coat. Season to taste with salt and pepper. (can be made 1 day ahead. Cover and refrigerate.) Arrange arugula around edge of platter; mound potato salad in center. Sprinkle with chives.