Leeks are a mild, sweet member of the onion family. Farmers hill soil up around each stalk as it grows, blocking the sun so the stalk stays pale and tender. That tight layering keeps leeks nice and tender, but can also trap dirt, so make sure halve them lengthwise and rinse between the layers before cooking. Softened slowly in butter they turn silky and sweet, the classic start to soups, stews, and gratins. Rich in vitamins, antioxidants, and fiber, and freshly harvested, they're a versatile choice for everyday cooking.