Prepare the dressing by combining mayonnaise, sour cream, white wine vinegar, Dijon mustard, celery salt and black pepper together in a large bowl. Stir well to combine then set aside.

Use a thin julienne blade attachment on a mandoline to cut the turnips into matchsticks. Roughly cut them in half before adding them to the dressing.

When all the turnips had been cut, turn to coat in the dressing. Taste for seasoning and add more black pepper if necessary. Finally, add some chopped fresh chives and transfer to a serving platter or bowl.

Store in the fridge (covered) until required.