Prepare cucumber, carrot, egg, and tuna. Slice the cucumber into thin strips and sprinkle with salt.
Beat the eggs and cook into thin omelets, then slice.
Slice the carrots thinly and lightly sauté them in a pan.
Place boiled cabbage leaves on a sheet of seaweed instead of rice.
On top of the cabbage, add the cucumber, carrot, egg, tuna, and pickled radish you prepared.
Drizzle mustard sauce, roll it up, and slice.