These odd-looking roots, which once had sprouts of celery stalks on them, can add an amazing flavor to puréed soups or roasts. Think Celery flavor mixed with potato-like texture, but a bit less starchy. Wash and shave off the skin and knobby roots (usually a paring knife works better than a vegetable peeler), then cut into 1' square and roast with other root veggies, or toss in a potato leek soup.