These are the fat cousins of skinny green onions. They grow in cinder-like earth and trap gritty particles within their white stalks.

To clean leeks. Cut off tops as you would on green onions, then insert your knife at a point 1 to 2 inches below the green and split up through the tops. Usually you can see the black dirt under the white skin of the leek. It is at this point that you split the leeks. Insert the knife twice, cutting in half one way, then the other, dividing the upper part of the leek into fourths.

Once they have been quartered swish tops through cold water and wash out all the grit. Cut off roots and use the rest.