Tuna Mayo Onigiri For A Creamy Rich On-The-Go Recipe

by Joost Nusselder | Updated:  August 30, 2022

17 easy recipes anyone can make...

All the tips you'll need to get started in Japanese cooking with, FOR A LIMITED TIME, FREE as our first email: the complete Japanese with ease cookbook.

We'll only use your email address for our newsletter and respect your privacy

I love creating free content full of tips for my readers, you. I don't accept paid sponsorships, my opinion is my own, but if you find my recommendations helpful and you end up buying something you like through one of my links, I could earn a commission at no extra cost to you. Learn more

Check out our new cookbook

Bitemybun's family recipes with complete meal planner and recipe guide.

Try it out for free with Kindle Unlimited:

Read for free

Tuna mayo is a classic sushi combination, so it’s only natural to make it for your onigiri as well.

This is how you make delicious and creamy onigiri tuna to take with you.

Tuna mayo onigiri

How to make tuna mayo onigiri

Tuna mayo onigiri recipe

Tuna Mayo Onigiri Recipe

Joost Nusselder
Tuna mayo is a sushi favorite of many, so it's only natural to make some for your onigiri too. The perfect snack to take with you!
No ratings yet
Prep Time 45 mins
Cook Time 30 mins
Total Time 1 hr 15 mins
Course Snack
Cuisine Japanese
Servings 4 people

Ingredients
  

Steamed rice

  • 2 cups Japanese short-grain rice uncooked
  • cups water

For making onigiri

  • 1 tsp salt (sea salt or kosher; use half if you choose to use table salt)
  • 4 sheets nori (seaweed)
  • 1 can tuna
  • 3 tbsp kewpie Japanese mayonnaise
  • 2 tsp toasted black sesame seeds (to garnish)

Instructions
 

Preparing the steamed rice

  • Put your rice in a large rice bowl, gently wash it in a circular motion, and dispose of the water. Repeat this process around 3 – 4 times.
  • Allow the rice to soak in water for around 30 minutes. Move the rice into a rice sieve and allow it to drain completely. This should take around 15 minutes.
  • Now mix the rice and water in a pot with a heavy bottom, and cover it with a lid. Bring the rice to boil over medium heat.
  • Once the water boils, reduce the heat to the lowest setting, and then continue to cook while covered for around 12 – 13 minutes, or until the water is fully absorbed. After 12 minutes, open the pot to see if there's any water present, close the lid, and then continue cooking for an additional minute.
  • Remove the pot from the stove with the lid is on, and then allow the rice to sit for an additional 10 minutes. Next, move the rice to a large plate and fluff it with a rice scooper. Allow it to cool for some time, or until you can comfortably hold it in your hands without burning them. However, you shouldn’t allow the rice to cool down completely.

Preparing the onigiri fillings

  • As your rice soaks and drains for 45 minutes, start preparing the onigiri fillings.
  • For the tuna mayo filling, put the drained canned tuna in a bowl, add 2 tbsp of Japanese mayonnaise and ½ tbsp of soy sauce, and then mix them together.

Preparing the onigiri

  • Cut the nori sheets into thirds.
  • Wet your hands with water to prevent the rice from sticking to your hands.
  • Put some salt in your hands and then rub to spread around your palms. If you're using table salt, make sure that you use half since it's much salter compared to kosher salt.
  • Now scoop the warm rice (around 1/3rd of a cup) into one hand, and then create a small indentation in the middle of the rice. Put your fillings inside (about 1 to 2 tsp), and then use your hands to mold the rice around the indentation to cover the fillings.
  • Press the rice around the area with the filling to create a triangle shape from the rice. You can use 3 fingers (thumb, index, and middle fingers) to create a triangle corner. Ensure that your hands are firm to prevent the onigiri from falling apart. Also, make sure that you don’t squeeze your rice very tightly.
  • Use the nori to cover the onigiri.
  • Sprinkle some of the sesame seeds on top of each of the rice balls.
Keyword onigiri
Tried this recipe?Let us know how it was!

Cooking tips

  • If you don’t want to touch the rice at all, you can place a piece of plastic wrap in a rice bowl (or any small bowl) and put the rice on top. Sprinkle on some kosher salt (remember, salt is used to preserve the rice for a long time here).
  • Pull the plastic wrap corners and twist a few times.
  • Form into a triangle shape in the same manner as I described above. 

A heavy-bottom pot with a tight-fitting lid is recommended, as it’s thicker at the base. This means it absorbs and distributes heat better.

Favorite Asian Recipes
Favorite Asian Recipes

View the basics of making onigiri here in this video:

Favorite ingredients

Kewpie mayo is the Japanese mayo of choice of course, so you have to have it to make the perfect tuna mayo onigiri recipe:

kewpie Japanese mayonnaise

(view more images)

Onigiri is easiest to make if you have rice with the right stickiness that’s easy to mold into shapes. That’s why I use this Nozomi short grain rice to make them:

Nozomi short grain sushi rice

(view more images)

Tips and techniques for making Japanese rice balls

Always make sure to use freshly cooked rice

This is the key step that’ll ensure you get the perfect onigiri results! Before making the rice balls, allow your rice to cool slightly.

However, the rice needs to be warm, but not cold when preparing.

Make your hands wet

Always make sure that you wet your hands with water. This prevents the rice from sticking to your hands.

You should always have a bowl of water on your countertop, as this makes things easier!

Rub some salt on your hands

You should salt both your hands and then rub them to spread the salt evenly. This assists in preserving the onigiri, as well as flavoring the rice balls.

Apply a considerable amount of pressure

Don’t apply too much pressure on your rice. This prevents the rice from falling apart as you shape your rice balls. You can opt to shape them into a typical ball, cylinder, or even triangle-shaped onigiri like these.

Avoid squeezing the rice too tight.

Use a kitchen towel to preserve them if you want to use them the following day

If you’re preparing the rice balls for lunch the next day, but you don’t want to prepare them the day of, you can use the following trick. Wrap the finished products in plastic wrap, and then wrap them using a kitchen towel.

This protects the rice ball from being excessively cold as you keep them in your fridge. It’s important to note that rice gets hard when refrigerated. But this easy trick will ensure that your rice balls stay cool and safe.

Kewpie mayo substitute for onigiri

If you don’t have kewpie mayo, any other Japanese mayonnaise will do as well of course, but you might not have that either.

You can always substitute kewpie in your onigiri with regular mayo by adding a little sugar and rice vinegar (or other vinegar if you don’t have it). Kewpie is a little more sweet and sour so adding those in small amounts to taste will come close.

Also read: what’s the difference between kewpie Japanese and American mayo?

Recipe variations

When following this recipe, it’s important to note that the fillings can vary. You should use your favorite ones! You can put almost anything you want in Japanese rice balls.

Try putting pickled plums, grilled salmon, pork, beef, dried bonito flakes (katsuobushi) with soy sauce seasoning, turkey, or tuna with mayonnaise.

Onigiri-rice-balls-recipe-7
Onigiri-rice-balls-recipe-6
Onigiri-rice-balls-recipe-4
Onigiri-rice-balls-recipe-3
Onigiri-rice-balls-recipe-2

Also read: if you’d like to try out more onigiri flavors, check out these top recipes

Check out our new cookbook

Bitemybun's family recipes with complete meal planner and recipe guide.

Try it out for free with Kindle Unlimited:

Read for free

Joost Nusselder, the founder of Bite My Bun is a content marketer, dad and loves trying out new food with Japanese food at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.