While the rice is cooking, flake fish into small pieces and add to a large bowl with scallions and mayo. Mix until well incorporated and season with wasabi salt, if desired. Set aside.

When rice is tender and the water is absorbed, sprinkle with rice vinegar and mix to incorporate. Spread rice on a rimmed baking sheet to cool slightly, sprinkle with a pinch of Kosher Salt.

Pour two tablespoons of Furikake or sesame seeds on a small plate and prepare the Onigiri station with rice, salmon salad, a bowl of water to keep your hands wet, an 8" x 8" sheet of plastic wrap and the nori strips.

Scoop a couple tablespoons of rice and set on the plastic wrap. Dip your fingertips in the water bowl and pat the rice into a circle. Then add a couple teaspoons of the filling to the center. Then, top the filling with another 2 tablespoons of rice.

Gather up the sides of the plastic wrap and twist to close. Then, form the rice ball just like a meat ball, inside the plastic wrap.

Then, slightly loosen the twist in the plastic wrap, but keep it closed. Gently flatten the rice ball and use the natural triangle shape between your finger and thumb to shape the sides into a triangle. Be careful when you flatten it to avoid squishing out the filling. Unwrap the plastic wrap.

Take one strip of the toasted nori and lay it vertically over the front of the Onigiri, just a little bit from the top. Then pick up the Onigiri from the top, with the plastic wrap, and let the bottom of the plastic wrap fall away and fold the nori around the bottom of the Onigiri. Let go of the plastic wrap.

Hold the Onigiri by the strip of nori. Trim the back end of the nori as needed to fit. Then, gently roll the sides in the furikake or sesame seeds. Set finished Onigiri on a plate and continue to make desired number of Onigiri.