Spicy Tuna Onigiri. Rice balls wrapped in roasted seaweed and stuffed with creamy spicy mayo tuna. A simple and satisfying snack, breakfast, or quick meal on the go. Great as picnic food too!

Popular in Japan!
This is a popular Japanese food item sold in convenience stores for their sheer convenience. If you love spicy tuna recipes, you will LOVE this.
On the mild side!
This version is also on the mild side and is less spicy than other versions. If you can’t tolerate spice at all, try my non-spicy Japanese Tuna Onigiri by clicking here.
Simple & delicious!
There is something so good and simple about spicy canned tuna onigiri! The taste of the spicy tuna mayo along with the soft rice and crispy seaweed is a wonderful combination of flavours and textures. I love making these when I have no idea what to eat and I have leftover rice in the fridge (yes you can use reheated leftover sushi rice for this recipe! Just maybe not past the 4 day mark).
Great for on the go!
Onigiri is not only pleasing to look at but very satisfying when you’re hungry! They’re great to take along for work or on the go because they can rest at room temperature for awhile without spoiling and are easy to pack.
Easy to make! No mould needed!
My canned tuna onigiri is easy to make because we’re using canned tuna! The spicy tuna filling for onigiri is only made of three ingredients: canned tuna, Japanese mayo and sriracha sauce!
You can use canned tuna in oil or in water, but my personal favourite is in oil. Yes, it’s a little fattier but the taste and texture of the tuna mayo mixture becomes so luscious and creamy!
For this recipe, I don’t use a fancy schmancy mould! Just cling film and your hands.
Comes together fast with cooked rice!
This Japanese spicy tuna onigiri recipe comes together in less than 15-20 minutes with cooked sushi rice depending on how fast you can assemble. You may also cook your rice the night before and store refrigerated in an airtight container. Then reheat in the microwave the same day for assembly.
Best eaten same day
Unfortunately, onigiri is not so delicious if you refrigerate them as the rice turns rock hard. So, if you’d like to make these for the next day, I suggest cooking your rice ahead of time, mixing your sriracha mayo tuna mixture and storing both in the fridge in airtight containers. Then on the day of, you can simply reheat the rice in the microwave, cut your roasted seaweed into little sheets and begin assembling.
YOU decide the amount of seaweed!
Usually when you see onigiri (as shown in my pictures), they typically look like this, but I’ve seen other ways to wrap them. Some with a larger sheet of roasted wrapping around the base and upwards or around the sides.
Sometimes you’ll even find them topped off with the inner filling like a little hat. It is up to you and how much roasted seaweed you’d like with your rice ball.
I like using a whole half sheet to cover one triangle! But for the traditional aesthetics of this dish, I’ve shown how to make it with a smaller piece of seaweed.
Tips for making Onigiri
Below are tips on making the best onigiri tuna recipe:
- Please use sushi rice or Calrose rice. This is especially important to ensure the rice sticks. Do not use jasmine, basmati, or sticky rice for this recipe.
- After cooking or reheating your sushi rice, allow it to cool to room temperature.
- Cover rice as it cools down to keep it moist
- I highly recommend canned tuna in oil or olive oil for this recipe for a luscious creamy center but if you only have canned tuna in water, which works fine too!
- Keep your roasted seaweed sheets in the package and only take it out when you’re ready to wrap the rice ball. This will keep the sheet from absorbing moisture in the air which will make it go soggy. But to be honest, once you adhere the seaweed wrapper to the rice triangle and if you’re not quick to eat (*ahem* foodies who like to take pictures of their food), it will go soggy anyway. Not like gross soggy but it won’t be dry and crispy. However, if you’re eating it immediately, then you’re fine!
More important tips
- Use cling film to help you mould the rice balls if you’re serving guests. This prevents rice from sticking all over the darn place and keep the food hygienic. However, if you’re making these for yourself the cling film can be omitted from the process. I would just suggest using clean wet hands when moulding the triangles or get ready for a sticky rice mess.
- Use a wet rice paddle to scoop your seasoned rice into the center of the cling film and spread it into a circular shape as best you can.
- Scoop the tuna mayo mixture into the center of the circle, this will help the rice evenly cover the filling.
- Lift the corners of the cling film and twist into a tight ball forcing the filling to go into the center of the rice. This way the filling won’t escape and stain your exterior rice.
- When adhering the rice ball to the seaweed, adhere it to the rough side of the sheet.
- Use dry hands to sprinkle sesame seeds on the rice ball or a sesame seed mess will prevail!
FAQ
Below are frequently asked questions about this spicy mayo tuna onigiri:
Where do I find sriracha sauce?
Any Asian grocer will carry this item in their sauce aisle. It has become popular, and you may even find it at your Western grocer.
How do I get my hands on Japanese mayo?
Most Asian, Korean, or Japanese grocers will carry this item. It’s found in the sauce or condiment aisle, and it comes in a plastic container with a red lid and clear bottle.
Can I use normal mayo?
Japanese mayo or Kewpie mayo is highly recommended for this, but normal mayo will work too!
Can I use another kind of rice for this recipe?
I would not recommend that. You need sushi rice because it is just sticky enough for the rice balls to remain intact. I would not recommend using jasmine, basmati rice and I would also avoid sticky rice as that is too sticky.
Where do I find canned tuna in oil?
Most western or Asian grocers will carry it. But if you can’t find it, feel free to use canned tuna in water.
Other recipes you may like!
If you enjoyed this spicy tuna mayo onigiri you may enjoy these other recipes:
JAPANESE TUNA ONIGIRI (non-spicy version!)
BULGOGI BEEF TRIANGLE KIMBAP
KOREAN TUNA MAYO RICE BALLS
PORK KATSU ONIGIRAZU
FOLDED KIMBAP
CHRISTMAS TEMARI SUSHI BALLS
PORK BELLY KIMBAP
ONIGIRAZU (SUSHI SANDWICH)
SPICY TUNA KIMBAP
For this recipe
You will need the following spicy tuna onigiri ingredients:
- 240 ml sushi rice, uncooked (or 1 ½ rice cooker cups)
- ½ or 2 sheets nori (this is based on personal preference)
- ½ teaspoon salt
- Optional: black sesame seeds for garnish
- Water to moisten hands and rice paddle
Spicy tuna filling:
- 104 grams canned tuna, drained of oil or water
- 1 ½ tablespoon Japanese mayo, or kewpie mayo
- 1 teaspoon sriracha sauce
How to make Spicy Tuna Onigiri
- Rinse your rice. Using your rice cooker or a pot, cook your rice as how you normally would. After it’s cooked, scoop the rice into a large bowl and season with salt. Mix well. Cover and let it cool to room temperature. Feel free to use leftover rice by reheating it in the microwave for 90 seconds covered.
- Meanwhile, in a small bowl mix together strained canned tuna, Japanese mayo and sriracha sauce. Set aside.
- Lay out a large fresh sheet of cling film (about 15 x 15 inches) on a clean surface where the film will cling.
- Moisten your rice paddle with water. Divide your cooked rice into four equal portions. Scoop one portion of the rice into the center of the cling film. Spread out evenly into a circle, about ½ – ¾ inch thick.
- Divide your spicy tuna mayo mixture into four equal portions. Scoop a portion into the center of the rice.
- Lift the corners of the cling film and twist into a ball, pushing the filling into the center of the rice ball.
- Gently flatten the rice ball until it’s about 2 inches thick. Then shape into a triangle using the L-shape of your thumb and pointer finger until you’re satisfied with the shape.
- Remove your nori from its packaging. Fold the sheet into half vertically and cut or gently tear at the fold. Then fold one of the halve sheets into half and fold again. Cut into 4 vertical strips. ***You can also use half a sheet of nori per rice ball (it’s up to you!)***
- Remove the triangle rice ball from the cling film and stick the rough side of the seaweed sheet on the base of the ball starting from the middle down. Garnish with black sesame seeds (optional). Enjoy!
Try it!
Well, I hope you give my Spicy Tuna Onigiri a try! It always excites me when you make my recipes and I hope this is one you try.
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Made this recipe and loved it?
If you could leave a star rating for my spicy onigiri, I would appreciate it 🙂 Thanks so much!
Take care,
Christie
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Spicy Tuna Onigiri (No mould needed!)
Ingredients
- 240 g sushi rice uncooked (or 1 ½ rice cooker cups)
- ½ or 2 sheets nori this is based on personal preference
- ½ teaspoon salt
- ½ teaspoon black sesame seeds Optional for garnish
- Water to moisten hands and rice paddle
Spicy tuna filling:
- 104 grams canned tuna drained of oil or water
- 1 ½ tablespoon Japanese mayo (normal mayo will work too)
- 1 teaspoon sriracha sauce
Instructions
- Rinse your rice. Using your rice cooker or a pot, cook your rice as how you normally would. After it’s cooked, scoop the rice into a large bowl and season with salt. Mix well. Cover and let it cool to room temperature. Feel free to use leftover rice by reheating it in the microwave for 90 seconds covered.
- Meanwhile, in a small bowl mix together strained canned tuna, Japanese mayo and sriracha sauce. Set aside.
- Lay out a large fresh sheet of cling film (about 15 x 15 inches) on a clean surface where the film will cling.
- Moisten your rice paddle with water. Divide your cooked rice into four equal portions. Scoop one portion of the rice into the center of the cling film. Spread out evenly into a circle, about ½ – ¾ inch thick.
- Divide your spicy tuna mayo mixture into four equal portions. Scoop a portion into the center of the rice.
- Lift the corners of the cling film and twist into a ball, pushing the filling into the center of the rice ball.
- Gently flatten the rice ball until it’s about 2 inches thick. Then shape into a triangle using the L-shape of your thumb and pointer finger until you’re satisfied with the shape.
- Remove your nori from its packaging. Fold the sheet into half vertically and cut or gently tear at the fold. Then fold one of the halve sheets into half and fold again. Cut into 4 vertical strips. ***You can also use half a sheet of nori per rice ball (it’s up to you!)***
- Remove the triangle rice ball from the cling film and stick the rough side of the seaweed sheet on the base of the ball starting from the middle down. Garnish with black sesame seeds (optional). Enjoy!
Mark
This was so simple and delicious. Even easier because I had leftover sushi rice in the fridge.
Barbara
I had been looking for a spicy tuna recipe and yours is the best. Thank you. I make onigiri for my Granddaughters school lunches. I have another Granddaughter at University in Japan and she is the one that taught me how to make Onigiri. Thank you and keep up the good work.
christieathome
Thank you so much Barbara for this very kind comment! I am so happy to hear this. It's so sweet that you make them onigiri for their lunches and your granddaughter taught you how to make it! 🙂 Have a lovely day!