To prepare leeks, remove any outer damaged leaves, then trim the top leaves, leaving 1-2 centimetres of green, and wash the leeks thoroughly under running cold water.
I find it easiest to shave off the top greenery with a large knife, cutting on the diagonal with the knife directed away from your body. This exposes more of the inside of the leek making it easier to wash out dirt. Wash thoroughly under running water, shake, and slice into cylinders or chunks, checking there is no more dirt as you go.
An easier method is to cut the leek lengthways after trimming. Wash thoroughly under running water, shake dry and cut into short lengths, then into ‘matchsticks’, or slice or chop.
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