Celery is a dieter’s delight, particularly in winter

It’s winter and the season has arrived when it’s hard to find fresh local produce — although I’ve heard that the Millerton Farm Market has amazing broccoli and cauliflower right now.Most nights, though, you’re going to have to find the vegetables for your dinner in the produce section of the nearest supermarket. Pretty much every food store in America sells celery, and that’s a good thing, for the most part. As anyone who’s ever been on a diet knows, celery is very low-fat and has a lot of nice fiber. It has some riboflavin and calcium and a lot of vitamins A and C and K.Weirdly, for such a bland food, it has a lot of sodium and natural sugars.And the fact that it’s got a lot of riboflavin is weird, too, since riboflavin is so strongly colored yellow or orange that it’s sometimes used to color foods with. Who knew that celery was so full of mystery.Just as mysterious as the regular green stalks are celery’s odd cousin, the knobby celery root (also known as celeriac). Even though they look so utterly different, they are in fact the same plant. Both are members of the apiaceae family, along with carrots and fennel; tons of herbs including dill, coriander and cumin; and the poisonous hemlock.Celeriac looks like it would be bad for you but in fact it’s not, and it’s also pretty yummy, with a mild creamy flavor and texture, kind of like the ugly cousin of a parsnip. Like the heroine of a romance novel, it is unattractive on the outside but exquisite on the inside.Needless to say, celery and celeriac offer similar nutrition benefits. In addition to the nutrients listed above, both also have a lot of vitamin B6, which is one of those incredible vitamins that does everything from regulating your metabolism to fighting dementia. They both also have a lot of potassium, which is good for calming muscle cramps (especially for growing children, especially in the calf muscles) and for reducing hypertension. A study at Harvard showed that men with hypertension who took in 4,300 milligrams of potassium a day (food sources are considered better than supplements) reduced their risk of stroke by 38 percent.Most people know what to do if they’re handed a stalk of celery (although most people don’t realize it’s super delicious if you slice it into 1/4-inch thick slices and then saute it in olive oil; throw in some pitted black olives, yum).But celeriac? The first thing you need to know of course is how to recognize it at the store.It’s not all that common so don’t be embarassed to do an Internet search for a celeriac image (and of course we have one on this page). It’s kind of a dirt-crusted fist-sized knob. Think of diamonds; they’re dirty when you dig them up, too, but with a little care you can shed the exterior and you’re left with … a diamond. Use a heavy knife (and a lot of care) to cut away the grimy outside layer. Then you can chop it up and steam and then mash it (mix it with potatoes and parsnips and turnips for the most amazing mashed you’ve ever had). Or you can julienne it and make the classic French céleri remoulade.Or you can try this two-celery soup from Patricia Wells, the most famous American chef in France since Julia Child. This recipe is adapted from her book “Bistro Cooking.”Soupe aux deux célerisAdapted from “Bistro Cooking”Four servingsOne small knob of celeriac (about a half pound), peeled and diced, five celery stalks, cut into medium rounds, 1 large leek, trimmed and rinsed and cut into thin rounds, a bouquet garni (with one sprig of thyme, 1 bay leaf and a few sprigs of parsley), a quart of good-quality chicken stock, coarse salt and freshly ground pepper to taste. For a garnish, use chopped fresh herbs such as chervil and parsley, both of which are in the apiaceae family.In a large pot, combine the celery, celeriac, leek, bouquet garni and chicken stock. Bring to a simmer and cook until the vegetables soften, about 25 minutes. The soup doesn’t require the use of a food mill or Cuisinart, but if you want it creamy, run it through before you garnish. Add salt and pepper to taste, garnish with herbs and serve hot with maybe a dollop of something white and creamy in the center, such as Greek yogurt.