2	pounds (960 g) Yukon Gold or red potatoes, cut into 1-inch (5 cm) chunks

2	tablespoons (30 ml) fat-free sour cream

1	tablespoon (15 ml) white wine vinegar

3/4	cup (90 g) thinly sliced celery

1/4	cup (40 g) minced red onion

1/4	cup (39 g) minced dill pickle

1/4	cup (56 g) reduced-fat mayonnaise

1/4	cup (57 g) nonfat plain yogurt

2	teaspoons (10 ml) Dijon mustard

1/2	teaspoon (2.5 ml) salt (optional)

freshly ground pepper

1	hard-cooked egg, sliced (optional)chopped fresh dill or flat-leaf parsley for garnish (optional)

1. Cook the potatoes in a large pot of boiling water for about 6 to 8 minutes, until tender. Drain well and transfer to a large bowl.
2. Add the sour cream and vinegar to the potatoes; stir to coat evenly. Add the red onion, celery, and chopped dill pickle.
3. In a small bowl, combine mayonnaise, yogurt, mustard, salt (if using) and pepper to taste.
4. Pour over potatoes and gently stir to evenly coat. Cover and refrigerate for at least 2 hours, or up to 8 hours.
5. Serve cold, garnishing just before serving with the sliced hard-cooked egg and chopped dill (if using).