Rice balls stuffed with creamy spicy mayo tuna wrapped in roasted seaweed. This quick and easy spicy tuna onigiri is ready in 20 minutes with cooked rice and minimal ingredients! It's a great as a snack, light meal, picnic food or breakfast.
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What is Spicy Tuna Onigiri?
Spicy Tuna Onigiri is a Japanese triangular shaped rice ball stuffed with a delicious creamy spicy tuna mayo mixture and wrapped in dry roasted seaweed and garnished with toasted sesame seeds.
It's a very popular Japanese food that is sold at many convenience stores or restaurants. There are even shops that specialize in making this rice ball with various fillings: from tuna to crab meat to spam and more!
Many hungry commuters and students in Japan love to eat this for breakfast, as a quick meal on-the-go or as a snack because it's cheap, filling and delicious!
I love making these whenever I have leftover cooked rice in the fridge that I can easily heat up in the microwave.
It's a fast recipe that requires simple ingredients and I always make this during a busy week when time is of the essence, when I don't know what to eat, have little energy to cook or when I want seafood!
Ingredients & Substitutes
Please scroll down to below recipe card for exact measurements.
- Cooked Short-Grain Rice (aka sushi rice or Calrose rice): Avoid using medium to long-grain rice as it won't be sticky enough to hold the rice ball. Do not use glutinous rice as that's too sticky.
- Nori: this is dry roasted seaweed and they come in large sheets in plastic sealed packages and sold at many Asian markets. Tip: store nori sheets in their packaging in a freezer-friendly bag in the freezer to maintain the flavor and dryness and it'll last a longer time.
- Salt
- Black Sesame Seeds (optional): or substitute with regular toasted sesame seeds
- Water: to moisten the rice paddle to prevent the rice from sticking to it.
Spicy Tuna Filling
- Canned tuna: I strongly recommend getting the kind canned in oil as it's much more tastier and smoother in texture but if you can't find this canned tuna in water works fine! Or substitute with canned cooked salmon.
- Japanese mayo (aka kewpie mayo): or substitute with normal mayonnaise
- Sriracha sauce: this is a spicy hot sauce that is actually from Thailand but you can substitute with any hot sauce that you enjoy.
Note: Most Asian grocers will carry these ingredients. You may find some at your select grocery store or online, like on Amazon.
Expert Tips
- Use canned tuna in oil over tuna in water for best flavor.
- Strain canned tuna to remove as much liquids as possible with a fine sieve by pressing it with a fork to push out the liquids.
- I recommend preparing fresh rice because it tastes better and the moisture holds the rice balls better. But you can always use reheated leftover rice.
- If you're preparing fresh rice, rinse the rice with cold running water until the water runs clear.
- Keep the cooked rice warm by covering it with a lid. If the rice is left out to dry out, it won't be sticky enough to hold shape.
- Wet the rice paddle or silicone spatula when working with rice to prevent it from sticking.
- Don't spread the rice out too thinly or the filling will leak out.
- Push the tuna filling into the center of the rice ball when shaping the ball, so it doesn't leak out.
- Use the L-shape between the thumb and index finger to shape the rice ball into a triangle.
- Firmly pack the rice ball so it holds shape and doesn't break apart later.
- Don't remove the nori from the packaging until assembly. The moisture in the air will make it soggy.
Instructions
Below are step-by-step instructions on how to make spicy tuna onigiri:
- First transfer freshly cooked or warm rice to a large bowl and season with salt. Mix well. Cover with a lid and keep warm. (Or feel free to use cold day-old rice that has been stored in an airtight container and reheat it in the microwave for 1-3 minutes covered until hot).
- Then open canned tuna and strain it of its liquids using a fine sieve. Remove as much of the liquids as possible by pressing it into the sieve using a fork. Then in a small bowl mix together strained canned tuna, Japanese mayo and sriracha sauce. Set aside.
- Next spread out a large fresh sheet of plastic wrap or cling film (about 15 x 15 inches) on a clean surface where the plastic will cling to (like a large ceramic plate or on a countertop with the corners taped down). Moisten the rice paddle or a silicone spatula with water and divide cooked rice into four equal portions.
- Then scoop one portion (about ¾ cup) of the warm rice into the center of the plastic wrap. Spread out evenly into a circle, about ½-inch thick.
- Next divide the spicy tuna mayo mixture into four equal portions. Scoop one portion of it into the center of the flattened rice.
- Lift and twist the corners of the plastic wrap so you form a circular rice ball while pushing the filling into the center. Gently flatten the rice ball until it’s about 1.75 inches thick. Then shape it into a triangle using the L-shape of your thumb and pointer finger until you’re satisfied with the shape.
- Then remove one sheet of nori from its packaging. Horizontally fold it into half to create a rectangle and cut at the fold line with clean scissors. Then horizontally fold the half sheet to create a square and fold again. Cut at the fold lines to make 4 vertical strips. (Or you can also use half a sheet of nori per rice ball if you prefer more seaweed!)
- Lastly remove the triangle rice ball from the plastic wrap and stick the rough side of the nori strip on the base of the ball starting from the middle down. Garnish with black sesame seeds and enjoy fresh!
Storage
- Tuna onigiri is best consumed fresh or within 12 hours. It's best not to eat room temperature rice for over 24 hours as rice is a breeding ground for bacteria.
- If you have leftovers, wrap them in plastic wrap and store in an airtight container in the fridge for up to 2 days. To reheat, microwave without the plastic wrap until the rice is warm again.
- Freezer-friendly? I don't recommend freezing onigiri as the rice will turn hard even after reheating.
Pairing Suggestions
Spicy tuna onigiri serves well with:
- starters like miso soup, Japanese crab corn salad or salad with Japanese ginger salad dressing or Korokke
- seafood dishes like shrimp tempura, panko shrimp or ebi mayo
- protein dishes like ramen eggs, chicken katsu or tonkatsu, Karaage, Teriyaki Tofu, Teriyaki Chicken, or Ginger Miso Salmon.
- rice dishes like Oyakodon, Omurice, Pork Katsu Onigirazu or Katsudon
- other noodle dishes like Yaki Udon, Creamy Mushroom Udon, or Udon Carbonara
- or Japanese egg salad sandwich
FAQ
Can I make spicy tuna onigiri in advance?
Yes, you can prepare the components (except for the nori strips) in advance and store the seasoned cooked rice and spicy tuna filling into separate airtight containers in the fridge for up to 4 days.
When ready to assemble the onigiri, reheat the seasoned rice in the microwave covered for 2-3 minutes until hot throughout and assemble according to instructions. Avoid removing the dry roasted nori out of the packaging until you're ready to assemble as this will turn soggy with air exposure.
How can I make spicy tuna onigiri not spicy?
That's simple you can easily omit the sriracha sauce! Check out my Japanese Tuna Onigiri for the non-spicy version.
What are other onigiri fillings?
Other fillings in onigiri include: sweet tobiko (fish roe), Mentaiko (or tarako or pollack/cod roe), imitation crab meat, fried spam seasoned with soy sauce and mirin, umeboshi (pickled plum), bonito flakes seasoned with soy sauce, Shrimp Tempura, tonkatsu and more!
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📖 Recipe
Quick & Easy Spicy Tuna Onigiri
Rice balls stuffed with creamy spicy mayo tuna wrapped in roasted seaweed. This quick and easy spicy tuna onigiri is ready in 20 minutes with cooked rice and minimal ingredients! It's a great as a snack, light meal, picnic food or breakfast.
Ingredients
- 3 cups cooked short grain rice (see Notes below for how much uncooked rice is needed if you're preparing fresh rice for this recipe)
- ½ sheet nori or feel free to use 2 sheets of nori if you prefer more
- ½ teaspoon salt
- ½ teaspoon black sesame seeds or regular toasted sesame seeds (optional)
- water to moisten rice paddle
Spicy Tuna Filling
- 5.29 oz canned tuna in oil ideally or use canned tuna in water
- 2 tablespoon mayonnaise or regular mayo
- 1 tablespoon sriracha sauce or any hot sauce
Instructions
- Transfer freshly cooked or warm rice to a large bowl and season with salt. Mix well. Cover with a lid and keep warm. (Or feel free to use cold day-old rice that has been stored in an airtight container and reheat it in the microwave for 1-3 minutes covered until hot).
- Open the canned tuna and strain it of its liquids using a fine sieve. Remove as much of the liquids as possible by pressing it into the sieve using a fork. Then in a small bowl mix together strained canned tuna, Japanese mayo and sriracha sauce. Set aside.
- Next spread out a large fresh sheet of plastic wrap or cling film (about 15 x 15 inches) on a clean surface where the plastic will cling to (like a large ceramic plate or on a countertop with the corners taped down). Moisten the rice paddle or a silicone spatula with water and divide cooked rice into four equal portions.
- Scoop one portion (¾ cup) of the warm rice into the center of the plastic wrap. Spread out evenly into a circle, about ½-inch thick.
- Divide the spicy tuna mayo mixture into four equal portions. Scoop one portion of it into the center of the flattened rice.
- Lift and twist the corners of the plastic wrap so you form a circular rice ball while pushing the filling into the center. Gently flatten the rice ball until it’s about 1.75 inches thick. Then shape it into a triangle using the L-shape of your thumb and pointer finger until you’re satisfied with the shape.
- Then remove one sheet of nori from its packaging. Horizontally fold it into half to create a rectangle and cut at the fold line with clean scissors. Then horizontally fold the half sheet to create a square and fold again. Cut at the fold lines to make 4 vertical strips. (Or you can also use half a sheet of nori per rice ball if you prefer more seaweed!)
- Remove the triangle rice ball from the plastic wrap and stick the rough side of the nori strip on the base of the ball starting from the middle down. Garnish with black sesame seeds and enjoy fresh!
Notes
To prepare freshly cooked rice for this recipe:
Please rinse 225 grams / 7.93 oz / 1 measuring cup + 2 tablespoon of uncooked sushi rice in cold running water until water runs clear and transfer to rice cooker filling with enough water to the instructed water line in the rice cooker pot.If you don't own a rice cooker, you can cook rice on the stovetop by following these instructions:
- Transfer rice into a medium-sized pot or pan, ideally non-stick.
- Next fill the pot with cold water. To know how much water to add, place your index finger above the rice and fill it up to the first knuckle line of the finger.
- Place pot of rice with water on stove top. Cover with a lid and bring to a boil on medium heat.
- Once you reaching boiling point, reduce to the lowest heat possible and keep covered. Let this cook over low heat for 12-14 minutes until most of the water has evaporated. If there's water in the base of the pot, continue to cook on low until there isn't.
- Take the pot off the heat. Let this rest covered for another 10-12 minutes so the rice can properly cook through a steaming process.
- The finished rice will be sticky (not wet) and you should be able to fluff it with a rice paddle.
Enjoyed my recipe?Please leave a 5 star review (be kind)! Tag me on social media @christieathome as I'd love to see your creations!
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Nutrition
Calories: 212kcal | Carbohydrates: 28g | Protein: 10g | Fat: 6g | Saturated Fat: 1g | Polyunsaturated Fat: 3g | Monounsaturated Fat: 1g | Trans Fat: 0.01g | Cholesterol: 16mg | Sodium: 510mg | Potassium: 88mg | Fiber: 1g | Sugar: 0.1g | Vitamin A: 47IU | Vitamin C: 3mg | Calcium: 13mg | Iron: 1mg
Millie
This was so yummy! Will be making it again.
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!
Mark
This was so simple and delicious. Even easier because I had leftover sushi rice in the fridge.