Creamy-Style Baked Potato Salad

1 1/2 cups fat-free mayonnaise 1/2 cup fat-free sour creaml 1/2 teaspoon Dijon mustard 1/2 teaspoon fresh-ground black pepper3 tablespoons chopped fresh chives2 pounds (about 3 large) baked Russet potatoes, chilled1 medium Bermuda onion, peeled and chopped fine4 ribs celery; strings removed and dicedAdd mayonnaise, sour cream, mustard, black pepper and chives to a large mixing bowl and, using a wire whisk, whisk together until combined. Stir in onion and celery until coated with dressing. Set aside.Leaving the potato skin on, trim the potato's ends and discard. Cut potatoes into 1/2-inch cubes; add to bowl and using a large rubber spatula stir and fold until coated with dressing. Taste and adjust seasoning with salt or pepper. Cover and refrigerate.Serves 12.Cook's note: Next time you make baked potatoes, cook three extra and you'll have a head start on this recipe.Nutrition values per serving: 113 calories (1.3 percent from fat), 0.2 g fat (0 saturated fat), 25.8 g carbohydrates, 2 g fiber, 2.3 g protein, 1 mg cholesterol, 436 mg sodium.