Leeks are a member of the allium family and most of their nutritive qualities are in the green parts – the bits that we tend to throw away. Avoid this by buying the smallest leeks you can find – they will be the most tender. Cut them in half lengthwise and rinse them well to wash out any sand trapped between the leaves. Eat all of it. use them as you would onions, or sauté and serve them as a side dish.