A leek is a vegetable that belongs to the Allium family, which also includes garlic, shallots, and onions. It is a cultivar of Allium ampeloprasum, the broadleaf wild leek, and the edible part of the plant is a bundle of leaf sheaths that is sometimes erroneously called a stem or stalk. Unlike onions, leeks do not form a tight bulb, but instead produce a long cylinder of bundled leaf sheaths that are generally blanched by pushing soil around them. Leeks have a sweet, oniony flavor that adds depth to soups, stews, pastas, and more. They can be used interchangeably with onions in most recipes for soups, casseroles, and stews to add a subtle, more complex flavor. Leeks can be sliced or chopped and used in place of onions or shallots in various dishes. They can also be enjoyed on their own, like a vegetable, as they have a sweet and mellow flavor when cooked. To prepare leeks, the tough tops are chopped off and the stringy roots are removed. The white and light green parts are then chopped into thin half-moons. Leeks can be cooked in various ways, such as roasting, grilling, and sautéing. The dark outer greens of leeks are also edible and can be used in stews, sautés, and pasta and grain dishes.