Cut your nori paper in half so that you have two rectangles.
Drain your tuna fish from any water or oil. Then place it in a small bowl and gently mash. Mix in the mayo, Sriracha and salt to taste.
Place about 2 tablespoons of rice on one side in a triangle shape. Spread it out evenly. Top with avocado first, then the cucumber, carrots. Add some tuna mixture and flatten it out. Sprinkle with sesame seeds. Grab the bottom left corner and fold it over. Tuck it in and roll it into a cone shape. You can wet it at the end corner to seal it.