once taught me a trick for cleaning leeks; here’s my variation as
it’s evolved over the years:
Rinse the leeks under running water to get rid of any large clumps
Cut off the green part just above where it starts to fan out from
the body the leek.
Cut the body of the leek in half lengthwise, starting about 1/2
inch from the root; do not cut through the root.
Rotate the leek 1/4 turn and make another lengthwise cut; the leek
should now be cut into quarters, but still joined at the root.
Fan out the "leaves" of the leek and wash well under running water.
Cut off the root.