The Jerusalem artichoke is an edible tuber--a subterranean stem-swelling--of an American sunflower, Helianthus tuberosus. It resembles the ginger root and its flavor, when cooked, is like that of an artichoke heart. J-chokes are frequently used as feed for livestock, but can also be eaten by humans raw, pickled, stewed or baked--and should be, because they're comparable to red meat in iron content.
The "Jerusalem" portion of this vegetable's name was long thought to be a modification of the Italian word for sunflower, girasole, but food-scholar Harold McGee has resurrected old evidence supporting the belief that "Jerusalem" may be a corruption of Terneuzen, the name of the town in Holland where, in 1613, it was cultivated and then, perhaps, exported to England.
French explorers first recorded their introduction, by Native Americans, to the Jerusalem artichoke in 1605. Shortly thereafter, samples of the new delicacy were shipped back to Europe, where it enjoyed a brief vogue as a tasty, easy-to-grow New World novelty. The topinambour--named for a group of visiting native Brazilians--soon fell from popularity when its one serious defect became evident: the Jerusalem artichoke generates enormous volumes of intestinal gas.
That's right--roughly 50% of the Jerusalem artichoke, by weight, is carbohydrates--inulin and fructosans--for which the human body has no digestive enzymes, making it at least 3 times as farty as any bean. Can anything be done to rescue the Jerusalem artichoke from gastronomic obscurity (and save the ass of the adventurous cook)? "Yes," says (again) McGee; cold storage helps, slicing the tubers and boiling in water for 15 minutes (with a quarter-teaspoon of cream of tartar or a tablespoon of lemon juice per quart of water to prevent discoloration) is better, and slow, covered baking in a 200°F oven for 24 hours will convert an even greater percentage of the indigestible carbohydrates into fructose. After that, you can use your Jerusalem artichokes just about anywhere you would use a potato, sweet potato or turnip.
Source: McGee, Harold; The Curious Cook; North Point Press; San Francisco; 1990