This video explains how to cut cucumbers when you're using them in sushi. Begin by peeling the cucumber. Cut off both the ends then cut it right down the middle so you have two pieces. Hold the cucumber in one hand and skin it with the other hand. This is to be done in one, long, slow, rotating motion. The knife needs to be moving up and down the whole time while you are cutting extremely thin. This requires a lot of patience and time. It is very important to not rush through this. When you get to the seeds you have reached the cut-off point. Roll everything together and place into a tall container. Soak the cucumbers for 20 minutes, then drain them. When you are ready, cut and serve.