Using a sharp knife, cut off the top tough dark green part of the leek and discard. Next, cut off the bottom root end of the leek.

Cut the white part of the leek in half lengthwise.

For rings, slice the trimmed leek crosswise into rings of your desired thickness (about ¼-inch).

For half moons, cut the trimmed leek in half lengthwise. Then, slice the leek crosswise into semi-circles of your desired thickness (about ¼-inch).

For matchsticks or julienne cuts, cut the trimmed leek in half lengthwise. Place the leek half cut-side down on the cutting board. Slice the leek lengthwise into thin strips (about ⅛-inch).

For dice cuts, cut the trimmed leek in half lengthwise. Place the leek half cut-side down on the cutting board. Slice the leek lengthwise into thin strips. Hold the strips together and cut crosswise into small cubes.

To wash the leeks, place the leeks in a large bowl and cover with cold water. Allow them to sit for 5 minutes, agitating occasionally. Pull the leeks out of the water and drain well in a colander before using as desired.