While rice cools combine 1 mayo packet, 3 sriracha packets and 1 drained can of tuna into a bowl and mix.
Take a palm size amount of rice and flatten it into a bowl shape in the palm of your hand.
Add a quarter sized ball of the tuna filling to the center of the rice in your hand.
Take another pinch of rice and roll it into a ball in your other hand and place it on top of the tuna pile to make something that looks like a tuna sandwich.
Use both hands to apply pressure to combine the top and bottom rice, incasing the tuna inside
Keep applying pressure until you have formed a rice ball, place a the ball on a flat surface and use your hands to mold the ball into a triangle shape.
Lastly cut a strip off of the seaweed sheet and apply water to one side of the sheet. Place the wet side of the seaweed strip under the the bottom part of the onigiri and fold the leftover seaweed up to the front of the onigiri. Done!
Optional: Place your onigiri in a hot pan with some sesame oil and fry both sides!