Wash the lettuce thoroughly and remove any excess water.
Julienne the carrots and lightly stir-fry them in a pan with a pinch of salt.
Drain the tuna by placing it in a strainer to remove excess oil.
Place a sheet of seaweed on a bamboo mat and spread the lettuce evenly over it.
Add tuna, stir-fried carrots, cucumber, and bell pepper on top.
Roll the ingredients tightly and cut into bite-sized pieces.