Celeriac is a variety of celery selected for it’s enlarged root. The flavor is similar to celery, but it is prepared like a root vegetable. Peel the skin of the celeriac bulb and cube. Then it can be roasted, stewed, or boiled and mashed. If you are looking for an easy way to prepare this unfamiliar vegetable try preparing mashed potatoes using half celeriac and half potatoes.