- Bring a large saucepan of water to the boil. Add the potatoes and simmer for 15-20 min, until tender. Drain and place in a large salad bowl. Allow to cool.
- Combine mayonnaise, sour cream, mustard and salt in a small bowl and add to potatoes.
- Gently mix in sliced celery, radishes and olives.
- Sprinkle with chives and season to taste with cracked black pepper.