Dice the tuna into cubes.
Cut the lettuce into bite-sized pieces.
Thinly slice the cucumber and carrot.
Put rice in a bowl.
Top the rice with lettuce, cucumber, carrot, avocado, and tuna.
Mix soy sauce, sesame oil, and wasabi sauce to make a dressing.
Drizzle the dressing over the ingredients.
Finish by sprinkling sesame seeds on top.