The leek is a vegetable related to onions, chives, and garlic. Also in this species are two very different vegetables: The elephant garlic (A. ampeloprasum var. ampeloprasum) grown for its bulbs, and kurrat which is grown for its leaves in Egypt and elsewhere in the Middle East.
Rather than forming a tight bulb such as the onion, the leek produces a long cylinder of bundled leaf sheaths which are generally blanched by pushing soil around them (trenching). They are generally considered to have a finer flavor than the common onion.