Celery roots, harvested in late fall, are big ugly-looking bulbs, but delish! They have a sweet refreshing flavor reminiscent of celery and parsley combined, and are an excellent source of vitamin K and fiber. To prepare, cut off the rooted end. Go deep past it, cutting off about a third of the bulb. Trim the skin, then boil, roast, or steam, as we do in Celery Root Hash, a pleasing, healthy alternative to regular hash browns. And just 64 calories per serving.