Like most other plants in the onion family, a good portion of the leek plant grows underground in sandy soil This means that you'll usually encounter a lot of dirt when you cut into leeks. But a little dirt never hurt anyone!
Cut the leek in half lengthwise
Turn it 90 degrees and cut horizontally, moving toward the root
After cutting to the desired size, fill a bowl with cold water and dump the leeks in, let it sit for a minute or two.
Take the leeks out with a slotted spoon, or with your hands. Don't drain the water with the leeks still in the bowl because all of the gross dirt settled at the bottom will just pour over the leeks. Dry them with paper towel and use in your fave recipe!