Place the lotus root slices into vinegared water while slicing it so that they won't discolour.
Add a little vinegar into a pot of boiling water, and boil the lotus roots for a few minutes. Do not over cook them as we want them to retain their crunch. Drain and chill them in ice water for awhile. Then drain them well.
Mix the cucumber and lotus root slices with salt, sugar and a dash of rice vinegar with your hands to let the flavours penetrate well. Then add the ham, tobiko or prawn roe, Jap mayo and Jap sesame dressing and mix well. Chill in the fridge before serving.