Jerusalem artichoke (also called sun choke) is in the sunflower family. It can be peeled, sliced or grated, and eaten raw. It's slightly sweet, and has the texture of a water chestnut. When cooked, it is much like a potato in texture, and can be served with butter, in stir fries, or like French fries.
If you wish to grow them, cut the sun choke knobs off and plant in you garden.
Each cut chunk will form a mature plant, with several sun chokes. They can take over a garden. When digging them up, if you miss any, you will have volunteers in your garden next year.
These are not only very tasty, but highly nutritious, naturally low in sugars, and get their characteristic sweetness from a compound called inulin, which is an important food source for good gut flora. So they are a prebiotic. Personally, I love them.
Seeeeya; Chief Longwind of the North