Rinse leeks. Cut off roots. The root ends of a leek should be discarded.
Cut off dark leafy greens that you do not plan to use, or save them for stock.
Slice leeks in half lengthwise.
Chop each half crosswise in 1/4 inch slices.
Place sliced leeks in a bowl of cold water. Agitate with your hands to remove dirt and grit that was trapped between the layers.
Scoop out clean leeks with a slotted spoon or drain with a colander. Dry completely with a salad spinner, then place in empty bowl. Proceed with using them for your recipe!
Method 2: Clean the Leeks Whole:
Cut a slit straight through the green parts of the leek. Insert the tip of a knife at about 1/4 inch below the lowest opening of the dark green part and cut to the end of the green leaves, leaving the white part of the leek uncut.
Fan open the leek and rinse thoroughly, running your fingers and the water between each layer. Cut off the leafy ends (can reserve to use for making stock).
Cut off and discard the stringy roots. Get ready for roasting, boiling, or sautéing, and ENJOY!
Notes
Which Part of the Leek Do You Use? The white and light green part of the leek are used for eating. The dark green leaves are not eaten on their own as they are tough, but they can be used for flavoring stocks. The very bottom root end of the leek is cut off and not eaten.