Leeks are a member of the lily family, related to the onion, with a slender white bulb, cylindrical stem and broad, flat leaves. They make a tasty addition to any soup or stew, and are particularly famous in Leek and Potato Soup. They contain sugards, dietary fiber and small amounts of protein. There is also some iron and carotene in the green leaves. They can be stored in a plastic bag in the refrigerator for up to 5 days.
When leeks grow, they often trap soil and grit between their leaves. The best way to clean them is to halve them lengthways, down to the bulb, but not all the way through. You can then fan out and rinse all the leaves, while keeping the leek intact. Leeks can be boiled or steamed, braised in stock, or sliced into rings and stir fried.