 Leaks are related to the onion family. They are sweet like onions when they're cooked, but unlike onions don't make your eyes water when you cut them. They have long straight white stalks with tough green leaves. Select fresh white stalks with bright fresh looking green leaves and avoid any that are wilted or damaged. To prepare leaks remove the toughest part of the green leaf and discard or reserve them to make stock and then trim the roots off at the base. Leaks are often very dirty with most of the dirt hidden within the layers. To clean them cut down its length without cutting through to the other side. Under running water full believes out with your hands and washed between the layers. There are a number of ways to cook leek once prepared, but because they are in season during the colder months I most often slice them up to use in hearty winter soups.