It won't win any beauty contests, but celeriac might take the award for being the vegetable with the most aliases. Celery root, celery knob/knob celery, turnip celery/turnip-rooted celery, Germany celery and celeri-rave .
Pronounced suh-LEHR-ee-ahk , the beige-skinned, knobby root has been around a long time, but typically gets overlooked by cooks unfamiliar with its attributes. In most parts of the country, celeriac is available in supermarket produce sections from October to April.
Celery raised for its upper stalks belongs to the same botanical family as the variety cultivated specifically for its enlarged root. Flavor of the creamy white flesh is similar to stalk celery, but more assertive. The texture is reminiscent of a turnip or potato.
Baseball-size celeriac is the most desirable; larger roots tend to be woody. When selecting, press the stalk end to be certain it's still firm, not spongy.
Allow 1/4- to 1/3-pound per serving. After purchase, celeriac may be stored in the refrigerator, wrapped in plastic, up to a week.
Prepare by rinsing with cold water, then thoroughly scrubbing the root with a vegetable brush (Step 1). Rinse again and pat dry with paper towels.
Using a sturdy, sharp knife, cut off and discard any stalks and the root end (Step 2). Avoid carbon knives, which discolor the flesh.
Cutting the root into slices before peeling makes it easier to remove the tough skin (Step 3). It may then be shredded, diced or cut julienne (Step 4).
The flesh will discolor unless dipped in acidulated water (three tablespoons of lemon juice or vinegar per quart of water). Keep the soaking time short, however, or it will absorb the liquid.
Raw celeriac makes a good addition to tossed green salads. Shredded or julienned and marinated in mustard-mayonnaise, vinaigrette or cream-style dressing, the vegetable is often served as a first course. (Prepare several hours ahead so flavors blend.)
Celeriac can be substituted for celery in soups and stews. Add 10 to 15 minutes before cooking is completed--overcooking quickly changes the vegetable from firm to mushy.
When served as an accompaniment to roasted meat, celeriac is often blanched, then combined with white sauce and baked or broiled.
It may also be simmered in water or broth until tender-crisp (about 15 minutes for julienne strips and 20 to 30 minutes for cubes), drained and tossed with butter and seasonings. Or, for a flavorful puree, cook celeriac along with a potato and blend in a food processor with a little butter, whipping cream and a dash of nutmeg.