What vegetable is used exclusively in a traditional navarin?

Navarin is a traditional French stew typically made with lamb and accompanied by various vegetables. The term "navarin" specifically refers to a dish that includes turnips, as they are a key ingredient that pairs well with the meat and enhances the dish's flavors.

Turnips add a unique texture and earthy flavor to the stew, which complements the richness of the lamb. While other vegetables like carrots, potatoes, and celery can be included in different variations of navarin or other stews, turnips hold a special place in this particular recipe, making them essential for achieving the authentic taste and character of a traditional navarin. Thus, their exclusive use in this dish is what makes them the right answer.