This Spicy Tuna Mayo Onigiri recipe starts with a creamy tuna filling that’s wrapped in sushi rice and nori for a low fat, flavorful snack or side dish.
Onigiri, also known as the Japanese rice ball, has been a staple in Japanese cuisine for centuries. These handheld snacks are versatile, convenient and addictively delicious.
If you’ve never tried Japanese rice balls before, you’re in for a treat!
I first tried onigiri when I was doing martial arts training in Taekwondo. Our sensei invited a group of us to his home for dinner one night after training. As he was originally from Japan, he prepared a traditional Japanese post-workout meal for us.
The rice balls he served us that night ignited my lifelong love for them! I’m going to show you exactly how I learned to make them that night, and how I’ve been making them ever since. Let’s get started!
What is Onigiri?
Onigiri has a rich history that dates back to ancient Japan. The earliest versions of onigiri were simply balls of cooked rice, meant to provide a portable and convenient meal for travelers and warriors. Over time, the technique of shaping the rice balls evolved, and different fillings and seasonings were introduced.
In modern times, onigiri remains a beloved food in Japan and has gained international recognition. It is readily available in convenience stores, supermarkets, and specialty shops, offering a wide range of flavors and fillings to suit different tastes.
Onigiri is so popular because of its simplicity, versatility and ability to provide a satisfying and portable meal.
Ingredients for this tuna mayo onigiri recipe
A short list of simple ingredients is all you’ll need to create these tasty Japanese rice balls:
- Japanese sushi rice. This is a must! Short-grain rice has a high starch content, making it easy to mold into shapes. It’s the best rice for this job.
- Canned tuna. Look for tuna that is packed in oil, which gives it more flavor.
- Nori. These are the sheets of dried seaweed that we will use to wrap the rice.
- Kewpie mayonnaise. This Japanese-style mayonnaise is sweeter and richer than traditional American mayo. You can totally substitute regular mayonnaise if you need to.
- Sriracha. It puts the “spicy” in spicy mayo.
How to make spicy tuna mayo onigiri
You’ll want to make the rice and let it cool for a few minutes so that you can handle it without it burning your hands.
Assembling the Rice Balls
Onigiri can be made into different shapes like triangles, spheres or burger-like shapes. Although the triangle shape is most common, I’m going to show you how my sensei taught me to make them.
Don’t worry about using an onigiri mold or plastic gloves. We’re doing this with our bare hands, people!
Lay a sheet of nori on a flat surface. Set up a bowl of water off to the side to dip your hands in.
Grab a small handful of rice (about 1/3 cup of rice) and place it down in the center of the nori. Use your hand to flatten it a little.
Make a small indentation in the center of the rice and fill it with a little spicy tuna mixture.
Then add some diced cucumbers.
Wet your hands again and get another small handful of rice to cover the tuna. Using wet hands, mold the rice around the tuna until the tuna is sealed in. Now, fold it up!
Moisten the corners of the nori and fold them, from corner to corner, over the rice. Turn the rice ball over, seam side down, when you’re finished.
Variations and Fillings for Japanese Rice Balls
While the traditional tuna onigiri recipe is super popular, there are other variations and onigiri fillings that are really good. Here are some to try:
- Teriyaki Tuna Mayo: Add a little sweet and savory flavor to your onigiri by mixing teriyaki sauce into the tuna mayo filling.
- Avocado Tuna Mayo: For a creamier and slightly tangy filling, adding mashed avocado to the tuna and mayo mixture creates a yummy twist.
- Vegetarian Options: Leave out the tuna and mix the cucumbers or even avocado with the spicy mayo. A personal favorite in our house is umeboshi plum paste, which adds salty umami flavor to vegetarian onigiri.
How to serve spicy tuna mayo onigiri
Onigiri is traditionally intended to be a quick snack or light meal that you can enjoy, grab-and-go style, anywhere you happen to be. Wrap it in plastic wrap to take along for lunch, a picnic or for a snack on busy days. It’s best enjoyed at room temperature.
Our favorite way to enjoy spicy tuna onigiri is at dinner time alongside a big salad with miso dressing. In fact, it’s our usual Tuesday night meal that the kids have grown up on!
How to Store Tuna Mayo Onigiri
Japanese rice balls are best enjoyed when they are fresh, at room temperature. If you have any left over, you can store them in the refrigerator for 1-2 days. Wrap each tuna mayo rice ball in plastic wrap to seal in the moisture, or they can easily dry out.
When you’re ready to enjoy your tuna-mayo onigiri again, warm it for a few seconds in the microwave so that it becomes soft again.
When you make this Spicy Tuna Mayo Onigiri recipe, I’d love to hear about it! Drop a rating or leave a comment below. Enjoy!
For more Asian-inspired recipes, try these:
For more rice-forward recipes, try these:
Spicy Tuna Mayo Onigiri Recipe (Japanese Rice Balls)
- 2 cups uncooked sushi rice
- 6 sheets nori
- 1 5 oz. can oil-packed tuna
- 1/2 cup cucumbers diced
- 2 Tbsp. kewpie mayonnaise
- 1 tsp. sriracha
Rice Cooker Instructions
- Place 2 cups of uncooked sushi rice into the rice cooker. Pour in 3 cups of water. Turn on the rice cooker. Once the rice cooker turns itself off, let the rice steam for 10-20 minutes. Remove the lid and let the rice cool before forming the rice balls.
- Bring 3 cups of water to a boil in a medium-sized saucepan. Stir in the 2 cups of sushi rice using a rice paddle or wooden spoon. Cover and reduce heat to low. Cook rice, covered, 15-20 minutes until the water is absorbed. Allow the rice to cool until you can safely handle it.
Making the Onigiri
- Drain the tuna and flake it with a fork. In a small mixing bowl, combine the tuna, sriracha and mayonnaise. Set aside.
- Seed and dice the cucumber. Set aside.
- Set up a small bowl of water to dip your hands in. Lay a nori sheet down on a flat surface. Using wet hands, scoop up a small handful of rice and place it onto the center of the nori. Form it into a flat disc.
- Top the rice with a spoonful of tuna and some cucumbers. Wet your hands again and get another small handful of rice. Place rice on top of the tuna. Form the rice into the shape of a hockey puck around the tuna.
- Wet your hands again. Using your fingertips, moisten the corners of the nori. Fold the corners over the rice, starting with the top right corner, bottom left corner, top left corner, bottom right corner.
- Serve with soy sauce for dipping.