Valley Flora Farm (Langlois) grows organic celeriac (also known as “celery root”) for late fall/early winter harvest. It is edible raw or cooked, and tastes similar to the stalks (the upper part of the stem) of common celery cultivars. Celeriac may be roasted, stewed, blanched, or mashed. Sliced celeriac occurs as an ingredient in soups, casseroles, and other savory dishes.
Each creamy-hearted celeriac is sold without the top and keeps quite well in the crisper: the shelf life of celeriac is approximately six to eight months if stored between 0 °C (32 °F) and 5 °C (41 °F), and not allowed to dry out. The freshness of the vegetable can be determined by viewing the hollowness of the vegetable; a fresh celeriac should not have a hollow center. The freshness of the vegetable will also be obvious from the taste; the older the vegetable, the less potent the celery flavor.
Check out this link for ideas about how to use celeriac: Celeriac is an Ugly Vegetable That’s Worthy of Love