You can make this perfect on-the-go Japanese snack right at home with this easy tuna onigiri recipe! This tuna onigiri is made with seasoned rice and stuffed with a delicious savory tuna mayo filling and wrapped with a crisp sheet of nori.
You can make this perfect on-the-go Japanese snack right at home with this easy tuna onigiri recipe! These tuna onigiri are made with seasoned rice and stuffed with a delicious savory tuna mayo filling and wrapped with a crisp sheet of nori.
When it comes to snacks, you have your sweet snacks, your savory snacks, and your satisfying snacks. These warm onigiri with tuna made with sweet and tangy sushi rice, spicy creamy tuna, and wrapped with a crisp nori sheet fall in the satisfying snack group.
Onigiri is a popular Japanese snack that can be easily customized with any type of filling that you prefer. These tuna mayo onigiri are the ideal snacks for when you are on the go, going on a road trip, packing for a picnic, or just craving something savory. Plus they are incredibly easy to make!
I am a huge snack person and anytime I am sitting around doing nothing, I am always on the hunt for a snack. This spicy tuna onigiri always hit the spot for me so I’m so excited to share this recipe with you! If you loved this tuna onigiri, you may also want to check out our spicy tuna crispy rice, Japanese egg sandwich, or Hawaiian spam musubi.
You can make your own deliciously savory, umami, and spicy tuna mayo onigiri from scratch with this recipe!
This onigiri with tuna is the perfect on-the-go snack for lunches, picnics, or whenever you are craving something savory that is satisfying!
I will show you how to make these tuna rice balls step-by-step with photos and a tips and tricks section for the most foolproof onigiri.
Kitchen Equipment
You will only need a few pieces of kitchen equipment to make this easy spicy tuna onigiri recipe!
Rice Cooker: Cooking rice with a rice cooker is so easy and requires little to no work. I’ve been using my Tiger rice cooker since college and it has never failed me once.
Mixing Bowls: you will need 2 mixing bowls to season your rice and mix the tuna filling together.
Onigiri Rice Mold: Using an onigiri rice moldwill 100% guarantee you have the best shaped and most compact onigiri. It is also the easiest way to shape the tuna onigiri as well! I found my onigiri mold on Amazon that comes in different sizes.
Ingredients
All the ingredients for this onigiri with tuna recipe can be found at your local Japanese or Asian grocery market or online! This is technically a spicy tuna onigiri because it contains sriracha, but you can always remove it for a less spicy filling.
Short grain sushi rice: you will need about 3 cups of cooked (1 1/2 cups uncooked) sushi rice. Warm short grain sushi rice is the best rice to use to absorb the seasoning as well as hold the signature triangular spicy tuna onigiri shape.
Rice Vinegar: rice vinegar adds a slight tangy sweetness to the rice as well as the filling. You can find rice vinegar online or at your local Asian grocery store.
Sugar: adds a touch of sweetness that balances out the rice vinegar in the rice seasoning.
Salt: seasons and brings out the other flavors in the onigiri with tuna.
Tuna: you will need 1 can (4.5 oz) of tuna of your choice. Make sure to thoroughly drain the tuna before mixing it with the other ingredients.
Kewpie Mayonnaise:kewpie mayonnaiseincorporates only egg yolks which creates a more custardy texture and a more rich and fatty mouthfeel. It adds a sweet and fruity with a hint of umami eggy flavor.
Sriracha:sriracha adds a spicy element to the tuna rice balls. You can add more or less sriracha based on your spicy preferences.
Green onion: small slices of green onion brightens the flavors of the tuna and mayo.
Toasted Nori: you will need crispy toasted nori or seaweed sheets to wrap around the onigiri with tuna. You can either wrap it entirely with the nori or simply around the base of the tuna rice balls.
Furikake seasoning:furikake seasoning is optional for garnish and additional flavor for the rice.
Substitutions and Additions
You can customize your own onigiri with tuna or any other filling that you please! I’ve listed some substitutions and additions below.
Substitutions
Instead of using tuna for your tuna rice balls, you can substitute any of the alternative fillings below.
Salmon
Bonito flakes
Spam
Fish Roe
Pickled plum
Additions
You can use any of the below suggestions to season your tuna mayo onigiri filling or to decorate the edges of the rice!
Furikake seasoning
Togarashi Seasoning
Toasted Sesame seeds
How to Make Tuna Onigiri
This tuna mayo onigiri recipe is so delicious and so easy to make! All you need to do is season the rice, mix the tuna, and assemble!
Season the Rice
Rinse and cook the rice. Place the rice in the bowl of your rice cooker and wash with water until the water runs clear. Then drain and add 2 cups of water and cook in the rice cooker.
Season the rice. In a small bowl, mix together the rice vinegar, sugar, and salt until combined. Once the rice is cooked, transfer the rice to a large mixing bowl and add the rice vinegar mixture and mix until combined. Cover and let the rice cool.
Spicy Tuna
Mix the spicy tuna. In a large mixing bowl, add the tuna, kewpie mayonnaise, sriracha, rice vinegar, green onion, and salt. Mix until combined.
Assemble
Use onigiri mold. Using an onigiri mold, add the seasoned rice to the mold filling it about halfway, and press your thumb or a measuring spoon into the rice to create a well. Then fill with about 1 tablespoon of the spicy tuna mixture and then cover with more rice. Firmly place the lid of the mold on top and then release it from the mold. Repeat until all the rice is used.
Add the nori. You have 2 options to add the nori. 1) Cut the nori into 4-inch x 1 1/2 inch wide strips and wrap one strip around the base of the tuna onigiri. 2) Cut the nori sheet in half and place the rice triangle near the top of one edge and fold the edges to cover the top. Then wrap the long end over the rice.
Garnish. Garnish the top/edges of the tuna mayo onigiri with furikake seasoning, toasted sesame seeds, or togarashi seasoning for more spice. Enjoy!
Tips for the Best Tuna Onigiri
Wash your rice. Washing your rice removes excess starch which results in the rice grains being more separated when cooked. If you do not wash your rice you could end up with overly mushy gelatinized rice when cooked.
Use sushi rice! I highly recommend using short-grain sushi rice for the best results. Sushi grain rice is plump and sticky which is optimal for absorbing the seasonings while also maintaining their sticky texture.
Season to taste. This is your spicy tuna onigiri. You can make it as spicy or non-spicy as you please by adding more or less sriracha to taste.
No mold? No problem. If you do not have an onigiri mold, you can easily shape your tuna rice balls by hand placing a sheet of plastic wrap on your work surface, adding rice, tuna mixture, and more rice, and then closing the plastic wrap and shaping it into a triangle with your hands.
Storage Instructions
These tuna mayo onigiri are best when served immediately. However, you can store these tuna rice balls wrapped in plastic wrap on the counter for up to 5 hours.
If more than that, you can store the onigiri with tuna in the refrigerator for up to 5 days. To reheat, sprinkle some water over the rice and cover with a wet paper towel to steam the rice in the microwave until warm.
Frequently Asked Q’s & A’s
What is onigiri?
Onigiri (お握り or 御握り), also known as omusubi (お結び), nigirimeshi (握り飯), or rice ball is one of the most popular on-the-go Japanese snacks that is found in convenience stores all over Japan. Japanese onigiri are sushi rice balls that are often shaped into triangles and wrapped in nori or seaweed sheets.
What do you put inside an onigiri?
There are countless different ways to fill an onigiri rice ball. You can fill it with tuna, salmon, pickled plum, kelp, spam, fish roe, teriyaki eel, bonito flakes and so much more.
What kind of rice is used for onigiri?
The best rice to use for this spicy tuna onigiri is short grain sushi rice. They are slightly sticky and plump which are optimal for absorbing the rice vinegar and sticking together to form its shape.
Why is my onigiri falling apart?
When creating tuna mayo onigiri, you must use warm short grain sushi rice that is slightly sticky and not too cold. The rice must be slightly warm to the touch to hold its shape. Also, you could fill the mold with a little more rice so when you press the mold, it compacts the rice tighter together.
You can make this perfect on-the-go Japanese snack right at home with this easy tuna onigiri recipe! This tuna onigiri is made with seasoned rice and stuffed with a delicious savory tuna mayo filling and wrapped with a crisp sheet of nori.
Rinse and cook the rice. Place the rice in the bowl of your rice cooker and wash with water until the water runs clear. Then drain and add 2 cups of water and cook in the rice cooker.
Season the rice. In a small bowl, mix together the rice vinegar, sugar and salt until combined. Once the rice is cooked, transfer the rice to a large mixing bowl and add the rice vinegar mixture and mix until combined. Cover and let the rice cool.
Spicy Tuna
Mix the spicy tuna. In a large mixing bowl, add the tuna, kewpie mayonnaise, sriracha, rice vinegar, green onion, and salt. Mix until combined.
Assemble
Use onigiri mold. Using an onigiri mold, add the seasoned rice to the mold filling it about halfway and press your thumb or a measuring spoon into the rice to create a well. Then fill with about 1 tablespoon of the spicy tuna mixture and then cover with more rice. Firmly place the lid of the mold on top and then release it from the mold. Repeat until all the rice is used.
Add the nori. You have 2 options to add the nori. 1) Cut the nori into 4-inch x 1 1/2-inch wide strips and wrap one strip around the base of the onigiri. 2) Cut the nori sheet in half and place the rice triangle near the top of one edge and fold the edges to cover the top. Then wrap the long end over the rice.
Garnish. Garnish the top/edges of the rice with furikake seasoning, toasted sesame seeds, or togarashi seasoning for more spice. Enjoy!
Notes
Wash your rice. Washing your rice removes excess starch that results in the rice grains being more separated when cooked. If you do not wash your rice you could end up with overly mushy gelatinized rice when cooked.
Use sushi rice! I highly recommend using short grain sushi rice for the best results. Sushi grain rice is plump and sticky which is optimal for absorbing the seasonings while also maintaining their sticky texture.
Season to taste. This is your spicy tuna onigiri. You can make it as spicy or non-spicy as you please by adding more or less sriracha to the taste.
No mold? No problem. If you do not have an onigiri mold, you can easily shape your tuna rice balls by hand placing a sheet of plastic wrap on your work surface, adding rice, tuna mixture, and more rice, and then closing the plastic wrap and shaping it into a triangle with your hands.
Rate & Review What did you think of this recipe?