In bowl, combine ⅓ cup celery, ¼ cup red onion, 1 pound turnips, 2 tablespoons fresh chives, ½ tablespoon Dijon mustard, 1 cup mayonnaise, and ½ tablespoon apple cider vinegar. Stir until well mixed.
⅓ cup celery, ¼ cup red onion, 2 tablespoons fresh chives, ½ tablespoon Dijon mustard, 1 cup mayonnaise, ½ tablespoon apple cider vinegar, 1 pound turnips