What to Look For: Celery root is roughly globe-shaped, with a knobby, uneven surface. The outside is a mottled brown color and the interior is creamy white. Choose firm celery root that feels heavy for its size, and avoid any that have soft spots.
How to Store: Wrap celery root loosely and store in the produce drawer of the refrigerator for up to two weeks.
When preparing this side dish, the celeriac, or celery root, can be roasted ahead of time; let it stand at room temperature until you're ready to add it to the mashed potatoes. Wild mushrooms sauteed with butter and rosemary make a mouthwatering garnish.
Some of fall's most distinctive flavors are showcased in this pureed celery root soup garnished with apple, chestnut, and brussels sprouts. Cardamom, anise, cinnamon, and coriander flavor the celery root while it simmers.