The best way to prep leeks for cooking.
The typical way to clean a leek—trim the leaf ends and the roots, cut the leek in half lengthwise, and wash grit and sediment from the halves under cold running water—doesn’t always do the job. The greatest concentration of dirt is usually found at the leek’s base, where the layers are tightly packed. Unless the leeks are going to be served halved (as in braised leeks), we prefer this method. We recommend using three times as much water as there are leeks for the rinsing step.