Leeks - Just use the white parts of the leeks. (Slice off and discard the roots and the dark green leafy parts from the top before using.) Be sure to rinse the leeks very well because dirt usually gets trapped down between the leaves. I like to use a salad spinner to get the chopped leeks very clean. 2 leeks will seem like a lot when you first start to chop them, but they will cook way down in the soup.