Leeks are the titan in the onion family. Mostly just the white and light green parts are eaten, though the darker green parts have plenty of flavor and can either be cooked longer to tenderize them, or used when making homemade soup stock.
Make sure to clean your leeks thoroughly as when leeks are grown soil is piled up around them.
Look for leeks that have long, white stems. The best size for leeks is medium and they should appear crisp.
Prefer leeks that have all or some of the roots still attached. The presence of the roots indicates that the leek is still intact; if the base of the leek has been cut, the flesh begins to dry out.
To prepare your leeks:
Leeks are an excellent source of vitamin C, good source of dietary fiber and iron.