Read more: 7 Must-Have Canned Foods And 7 To Avoid In Your Pantry Tuna mayo (it sounds like one word in Japan) has been a popular onigiri filling in Japan since 1983. So, going from tuna sandwich ...

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 ...