Elegant and refined, the leek is perhaps the most sophisticated member of the onion family. Its flavor is oniony but sweeter and more delicate than that of an onion or shallots.
Native to Western Asia and the Mediterranean, leeks are grown and enjoyed all over Europe. Leeks can also grow in most areas of the United States, although commercial production in the U.S. is centered in the Pacific Northwest.
The Greeks and Romans used leeks medicinally and as a food. A national emblem of Wales, leeks were worn on the helmets of Welsh soldiers to distinguish them from their Saxon enemies in battle.
Leeks are a very good source of vitamins A, C and K, folate and manganese. They're also a good source of dietary fiber, vitamin B6, iron and magnesium.
Some leeks are harvested in the season they've been planted, and others are harvested the following spring. Overwintered leeks are larger and stronger tasting than summer leeks.
Musselburgh is a well-known overwintering variety of leeks, with thick white stems. Welsh Wonder matures faster than other varieties, and Carentan Giant and King Richard (summer/fall leeks) are preferred in colder climates. Blue Solaise, an overwintering variety, is a French heirloom leek with a blue/green color. Dawn Giant, a summer variety, is an especially large, thick-stemmed variety.
Leeks can be eaten raw or cooked—boiled, braised, pureed, steamed or fried. They're also lovely in sauces and bouquets garnis, bundles of herbs that flavor soups and other dishes. With a mild onion flavor, soft, tender texture, and pretty, pale green color, leeks are a wonderful substitute for onions in recipes where you want something just a little more special.
Try substituting leeks for onions in most any dish, like soups, stir-fries and pizzas. Or serve them along with onions. Mushroom Artichoke Flatbread Pizza features artichokes and Kalamata olives with sauteed onions, leeks and mushrooms.
Roast a tray of mushrooms and sliced leeks with thyme until fragrant, and use as the base for a traditional bread stuffing that will contribute to a memorable holiday meal. Leeks are combined with noodles and button mushrooms and baked in a sour cream sauce in this comforting Savory Noodle Kugel with Leeks and Mushrooms.
Whip up a simple leek and carrot saute as an accompaniment to baked turkey or tempeh, or feature leeks in a starring role with French Leek Pie with Gruyere Cheese or Potato Leek Soup with Gruyere. Soba Noodles with Greens and Beans relies on sauteed leeks for a mild onion flavor, combined with a spicy, garlicky ginger sauce over wilted spinach, beans and soba noodles.
The edible portion of a leek is the white, onion-like base and the light green part of the stalk. Use the dark green tops to flavor soups and stocks, but remove them before serving, because they're tough.
Choose firm, straight, crisp leeks with white necks and dark green (or faintly blue-green) leaves. The bulbs should have no cracks or bruises.
Very large leeks are more fibrous than smaller ones, so look for leeks that are less than 1 1/2 inches in diameter.
Store leeks in the refrigerator, unwashed and untrimmed, loosely wrapped in a plastic or a produce bag, for a week or two.
To prepare, cut off the root and cut leeks in half lengthwise. Rinse well between the leek sections, or immerse in a bowl of water and swirl, allowing soil and sand to sink to the bottom.