Nothing hits quite like spicy tuna. And this Spicy Tuna Onigiri recipe takes that hit and adds in an extra kick – it’s a one-two combination. The deep umami notes in the tuna paired with the heat from the spicy sauce makes for an irresistible flavor fusion.

Spicy tuna is like your old high school friend – you know, the one that’s always dependable, consistent and always at your side, no matter where you go. Every sushi restaurant has a spicy tuna offering, because it’s delicious, it’s sought after wherever people are and it delivers that same deep umami flavor, every single time.

In today’s recipe, we’re going to capture that flavorful essence – in an onigiri.
What is Onigiri?
It’s a Japanese word that literally translates to “grasp” or “squeeze” but in this context, it’s a tasty ball or cone of rice (traditionally in Japanese cuisine), stuffed with all kinds of delicious fillings, and often with an outer wrap of nori (seaweed).

It’s kind of like the Japanese version of a sandwich and it’s the perfect on-the-go food because of how easy it is to hold and eat, especially for busy people on the move or young kids.
The Ingredients for Spicy Tuna Onigiri

Scroll down to the recipe card for exact measurements and directions.
- Sashimi Grade Tuna
- Sushi Rice (Asian Short Grain Rice)
- Furikake
- Roasted Seaweed
- Rice Vinegar
- Kewpie Mayo
- Sesame Oil
- Sriracha Sauce
The Equipment Needed
- Onigiri Press
- Rice Cooker
Cooking The Perfect Rice
The art of cooking the perfect rice for your Spicy Tuna Onigiri is key.
Start by rinsing your rice at least 3 times under cold running water – to eliminate the starch and any other foreign particles from the grains.
If you have a rice cooker, simply cook the rice following your rice cooker’s instructions.

If you don’t, or would rather like to do this on your stovetop, then add your 2 cups of rinsed rice into your pot with just enough water to pass the finger test.
For the finger test, you take your pointer finger, place it into the pot with your rice, and set it just on top of the rice line. Then add just enough water so that the water line reaches the first segment line on your pointer finger.
Then cover the pot with a lid (if your lid does not have a steam valve, leave the lid slightly cracked open) and bring it to a boil, cooking at high heat.
Once boiling, reduce the heat to low and simmer for about 25 minutes (cooking time may vary based on your pot’s size).
You will know when your rice is done, when all of the water has been absorbed and the rice kernels looks tender and chewy.
When the rice is fully cooked, scoop into a large mixing bowl and let rest.
Seasoning the Rice
In pot, combine rice vinegar, sugar, salt and the sesame oil and bring to a low boil – for about 5-10 minutes until the sugar and salt have completely dissolved. Let it stand and cool for about 10 minutes. (An alternative to this step is to buy ready-made sushi rice seasoning liquid at the store.)

Once the seasoning liquid has cooled to be just slightly warm, drizzle the liquid into your mixing bowl of cooked rice while stirring gently. Keep stirring until the wet combination of the seasoning liquid and the rice eventually transform into a sticky rice mixture.
Putting It All Together
Take your sashimi grade tuna and chop into small pieces.

Put the tuna in a mixing bowl and add in the kewpie mayo, sesame oil, a tablespoon of furikake and sriracha sauce until the tuna and sauce are fully combined.

Using your Onigiri press, lay down a layer of the onigiri rice to form the back of the onigiri. Then ladle in a spoonful of the tuna mixture – leaving a small area of rice along the edge of the onigiri (this is to adhere to the other half of the onigiri rice).

Then cover with more rice and press down firmly to seal the onigiri.
Flip the onigiri press upside down onto a plate and use the press to extract the onigiri onto the plate.

Wrap a nori strip at the bottom of the onigiri and dust the edges of the rice with furikake.
Optional: In a frying pan, spread a light layer of sesame oil, and lightly toast only the front and back of the onigiri.
Plate and serve!
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Equipment
- 1 Rice Cooker
Ingredients
- 4 ounces Tuna, (sushi grade)
- 2 cups Sushi Rice, (asian short grain rice)
- 4 tablespoons Furikake
- 1 pack Roasted Seaweed
- 0.5 cups Rice Vinegar
- 2 tablespoons Sugar, (white)
- 1 tablespoon Sesame Oil
- 1 teaspoon Salt
- 3 tablespoons Kewpie Mayo
- 1 tablespoons Sriracha Sauce
Instructions
Cooking The Perfect Rice
- The art of cooking the perfect rice for your Spicy Tuna Onigiri is key.
- Start by rinsing your rice at least 3 times under cold running water – to eliminate the starch and any other foreign particles from the grains.
- If you have a rice cooker, simply cook the rice following your rice cooker's instructions.
- If you don't, or would rather like to do this on your stovetop, then add your 2 cups of rinsed rice into your pot with just enough water to pass the finger test.
- For the finger test, you take your pointer finger, place it into the pot with your rice, and set it just on top of the rice line. Then add just enough water so that the water line reaches the first segment line on your pointer finger.
- Then cover the pot with a lid (if your lid does not have a steam valve, leave the lid slightly cracked open) and bring it to a boil, cooking at high heat.
- Once boiling, reduce the heat to low and simmer for about 25 minutes (cooking time may vary based on your pot's size).
- You will know when your rice is done, when all of the water has been absorbed and the rice kernels looks tender and chewy.
- When the rice is fully cooked, scoop into a large mixing bowl and let rest.
Seasoning the Rice
- In pot, combine rice vinegar, sugar, salt and the sesame oil and bring to a low boil – for about 5-10 minutes until the sugar and salt have completely dissolved. Let it stand and cool for about 10 minutes.
- Once the seasoning liquid has cooled to be just slightly warm, drizzle the liquid into your mixing bowl of cooked rice while stirring gently. Keep stirring until the wet combination of the seasoning liquid and the rice eventually transform into a sticky rice mixture.
Putting It All Together
- Take your sashimi grade tuna and chop into small pieces.
- Put the tuna in a mixing bowl and add in the kewpie mayo, sesame oil, a tablespoon of furikake and sriracha sauce until the tuna and sauce are fully combined.
- Using your Onigiri press, lay down a layer of the onigiri rice to form the back of the onigiri. Then ladle in a spoonful of the tuna mixture – leaving a small area of rice along the edge of the onigiri (this is to adhere to the other half of the onigiri rice).
- Then cover with more rice and press down firmly to seal the onigiri.
- Flip the onigiri press upside down onto a plate and use the press to extract the onigiri onto the plate.
- Wrap a nori strip at the bottom of the onigiri and dust the edges of the rice with furikake.
- Optional: In a frying pan, spread a light layer of sesame oil, and lightly toast only the front and back of the onigiri.
- Plate and serve!
Notes
Nutrition
*Nutritional information is just an estimate derived by an online calculation tool.
FAQ
What is a good filling for Onigiri?
Spicy Tuna Filling or Seared Salmon Filling are both great options for Onigiri.
Should you eat onigiri warm or cold?
You can lightly toast the onigiri in a frying pan, if you’d like it warm or just eat it cold – it’s good either way!


Paula
My kids and I loved this spicy onigri. Delish!