1-Rinse and Cook Rice: Rinse the rice under cold water until the water runs clear, then drain well for the best texture. Cook it with water in a rice cooker or on the stove for 16 to 18 minutes on low heat, then let it rest covered for 10 minutes. This step ensures the rice is sticky and ready for shaping, which is key for that traditional feel.

2-Prepare Filling: While the rice cools slightly, prepare the tuna filling by combining the drained tuna, mayonnaise, sriracha hot sauce, rice vinegar, and finely sliced scallions in a bowl. This mixture gives the spicy tuna onigiri its signature zing.

3-Assemble Onigiri: To assemble, moisten your hands with room temperature water and sprinkle them with kosher salt to prevent sticking. Take about half a cup of rice, shape it into a thick oblong in one palm, add a tablespoon of the filling in the center, and enclose it with more rice. Shape the rice ball into a wide triangular form without pressing too hard to keep it light and fluffy. Sprinkle with toasted black sesame seeds if you like, then wrap each onigiri in a piece of nori and top with a small spoonful of tuna. Serve immediately for the freshest taste.