Finely chop the cucumber and Cheongyang chili peppers.
Drain the oil from the canned tuna and place it in a bowl.
Add mayonnaise and the chopped chili peppers to the tuna and mix well.
Place a sheet of seaweed on the bamboo mat and spread the rice thinly over it.
Add the chopped cucumber, spicy tuna mixture, and pickled radish on top of the rice.
Evenly arrange the ingredients and roll the kimbap tightly.
Cut into bite-sized pieces.