Cook the rice: Start by cooking your short grain or sushi rice. If you have a rice cooker or instant pot, follow the instructions for perfectly fluffy rice. If cooking on the stovetop, rinse the rice a few times until the water runs clear, then cook it with the right amount of water. Once it's done, let it sit for a few minutes, then fluff it up with a spoon.

Season the rice: While the rice is still warm, sprinkle in some salt and gently mix. This helps bring out the flavor and gives the rice that classic onigiri taste. Let the rice cool to room temperature so it's easier to handle.

Prepare the tuna mayo filling: Drain the canned tuna well and place it in a bowl. Mix it with Japanese mayo until creamy and well combined. Add a dash of sriracha or chili flakes if you like a little heat for a spicy tuna twist! (I did not.)

Shape the onigiri: I used plastic wrap to shape the onigiri for less mess. If you are using your hands, wet your hands with water to prevent the rice from sticking, then rub a little salt on your palms. Take a scoop of rice and gently flatten it in your hand. Add a spoonful of the tuna filling in the center. Carefully fold the rice around the filling and shape it into a triangle or ball. Garnish with sesame seeds or furikake for added flavor. Repeat with the remaining rice and filling. (If you're using a mold, press the rice in, add the filling, and top it with more rice before pressing it into shape.)

Add the nori: Cut the nori sheet into strips or your preferred shape,  and wrap one around the bottom of each rice ball. This makes it easier to hold and adds a nice crunch.

Garnish and enjoy: For extra flavor, sprinkle your onigiri with sesame seeds or furikake. That's it! Fresh, simple, and delicious. Enjoy!