Leeks (Allium ampeloprasum var. porrum) are mild, sweet members of the Allium family with long white and pale-green stalks that transition into broad, dark green leaves. Related to onions, garlic, shallots, chives, and green onions, leeks provide organosulfur compounds along with flavonoids, particularly kaempferol derivatives. Their flavor becomes soft and sweet when cooked, making them especially well suited to soups, stews, sautés, braises, egg dishes, and roasted vegetables. The tender white and light-green portions are most commonly used in cooking, while the darker green leaves can also be used in stocks, soups, and other preparations.