Tuna Mayo Onigiri is a popular variation of the classic Japanese rice ball, filled with a delicious mixture of canned tuna and mayonnaise. To make this flavorful recipe, you will need cooked Japanese short-grain rice, canned tuna, mayonnaise, soy sauce, salt, and optional toppings like sesame seeds or chopped green onions. Start by draining the canned tuna and mixing it with mayonnaise, soy sauce, and a pinch of salt. Take a small handful of rice and shape it into a triangle or oval shape. Make a small indentation in the center of the rice and add a spoonful of the tuna mayo mixture. Gently mold the rice around the filling, ensuring it is fully enclosed. Repeat the process with the remaining rice and filling. For added flavor and texture, you can roll the finished onigiri in sesame seeds or sprinkle chopped green onions on top. Tuna Mayo Onigiri is a delicious and satisfying option for lunchboxes, picnics, or a quick snack.