Dice 1/8 onion and chop green onions.
Drain tuna oil/water from can and transfer into a bowl.
Add diced onions, green onions, mayo, salt & pepper and mix.
Shave the cucumber horizontally with a peeler.
Get cooked rice, add a dash of sesame oil and mix.
Mold and shape rice into tiny round balls.
Place a cucumber strip on a flat surface, place the rice ball and gently roll and wrap the rice ball.
Add the tuna mixture on top, sprinkle chili flakes (optional) and enjoy!