Boil the chicken breast, let it cool, and shred it along the grain.
Julienne the carrots and sauté them in a pan.
Julienne the cucumber.
Beat the egg, make a thin omelet, and cut it into strips.
Place a sheet of seaweed on the bamboo mat and spread the rice thinly over it.
Add the shredded chicken breast, carrots, cucumber, and egg on top of the rice.
Roll tightly and slice to serve.