Tuna Mayo Onigiri Recipe – Japanese Rice Ball

tuna mayo onigiri recipe header

Ah, onigiri ( おにぎり ) – the beloved Japanese rice ball.

If you’ve ever watched any Japanese show or anime (e.g. Pokemon), you have probably seen an onigiri at some point. Although Westerners may have been tricked by lousy English dubs into thinking it was a jelly filled donut (infamously done by Pokemon)…

tuna mayo onigiri recipe

Onigiri is basically a ball of rice (usually shaped into a triangle or sphere), stuffed with a variety of different fillings. The most basic onigiri is actually just rice and salt. It is also often wrapped in nori (i.e. dried seaweed). Despite its simplicity, onigiri is one of the most traditional, popular and famous foods throughout all of Japan.

There are infinite varieties of onigiri, but I’m going to make one of the modern classics (and my favourite) — tuna mayonnaise onigiri.

How to make Tuna Mayo Onigiri Recipe (ツナマヨおにぎり)

This tuna mayo onigiri recipe is probably enough to make about four onigiri…depending on how big you make them 😉.

Ingredients

ItemQuantity
Freshly cooked Japanese rice2 cups
Canned tuna1 can (80g)
Japanese mayo (or Western mayo if that’s all you have)1 – 2 tablespoons
Salta pinch or two per onigiri

Optional ingredients

  • Soy sauce
  • Nori (dried seaweed sheets)
  • Any other seasoning you want

Equipment / Tools

  • Rice cooker (to cook rice)
  • A bowl for mixing + chopsticks or spoon to mix with
  • Your hands
  • Cold water (this should be an ingredient maybe?)
  • Plastic food wrap / saran wrap (optional – easy way to form onigiri)

Quick instructions

Cook rice. Mix tuna and mayo together. Form rice ball around mixture. Wrap with seaweed. Eat.

Detailed Instructions

Step 1: Cook rice

tuna mayo onigiri recipe

Cook some fresh rice. If you don’t know how, check out this article: How to cook rice with a rice cooker

The rice needs to be short-grain or medium-grain, so that it will stick together. If you use jasmine or long-grained rice, you are going to have a hell of a time making onigiri.

Step 2: Make tuna mayo mixture

While the rice is cooking, prepare your tuna and Japanese mayo mixture in a bowl. First, drain as much of the liquid/oil from the tuna as possible. Then add your mayo and mix together. You can also add salt, pepper, or any other seasoning you want. I usually like to add a touch of soy sauce.

tuna mayo onigiri recipe mixture

Taste your mixture to make sure it’s alright.

What’s the difference between Japanese mayo and Western mayo?

Japanese mayo (specifically the Kewpie brand) has become recognized as the king of mayonnaise over recent years. It is actually made with similar ingredients to Western mayo, so what makes it taste so good?

  • Japanese mayo uses only egg yolks while Western mayo uses the entire egg.
  • Japanese mayo uses rice vinegar or apple cider vinegar while Western mayo uses distilled vinegar.
  • One extra secret ingredient in Japanese mayo is MSG. Although MSG has a bad rep, it has actually been proven to not cause any of its infamous negative health effects.

The result of these specific ingredient choices is that Japanese mayo tastes creamier, richer, slight sweeter, and far superior to it’s distant cousin. If you’ve never tried Japanese mayo, you really should.

https://www.thrillist.com/eat/nation/what-is-kewpie-mayo-japanese-mayonnaise

Step 3: Take rice out and let it cool down a bit

tuna mayo onigiri recipe

When the rice is finished cooking, turn off the rice cooker, and take the pot out of the rice cooker to let it cool down a bit. We need the rice to still be warm, but not so hot that it will burn your hands. If you want to quicken the cooling process, you can spread it out on a plate or pan, although you will then have more dishes to wash.

Step 4: Shaping the onigiri – 2 options

There are a couple methods to shape your onigiri — the classic way (using your hands and water), and the easier way (with plastic wrap). You could also use onigiri molds, but that requires buying more stuff.

Option 1: Easy method with plastic wrap

This is the 1000x easier method of making onigiri, and also helps keeps your hands clean. The only downside is that you need to waste plastic wrap which costs money, and is not great for the environment.

tuna mayo onigiri recipe
  1. First tear off a decent sized piece of plastic wrap (about the size of a sushi mat would do). Depends on how big of an onigiri you want to make. Place the wrap flat on your table.
  2. Put one big scoop of rice in the middle of plastic wrap and flatten it out a little bit. Sprinkle some salt onto the rice if you like.
  3. Take a spoonful of your mixture and put it into the middle of the rice. Don’t put too much in, or you won’t be able to close the ball.
  4. Pull the edges of the plastic wrap together, and mold the rice into a ball (or any shape you want).
  5. If you want that classic triangle shape, check out see Step 4a.
Option 2: Traditional / classic method with your bare hands

If you want to be a real onigiri master, then you need to do it with your bare hands. The trick is to wet your hands so that the rice doesn’t stick to your fingers.

1. Fill a bowl with some cold water. Wet your hands with the water. The water helps prevent the rice from sticking to your hands. Your hands don’t need to be soaking wet, but just moist. If your hands are too wet, the onigiri will also become watery.

tuna mayo onigiri recipe

2. (optional) Spread a pinch of salt into the palm your hands. It will naturally be mixed with the rice when you start shaping the onigiri. You can adjust more/less salt for taste after you try the first time. If you are trying to cut down on your salt intake, skip this step.

tuna mayo onigiri recipe

3. Scoop some rice into your left hand (about a bowl’s worth), and shape a small divot into the middle. The rice should sort of resemble a small bowl. If you’re left handed, you might find it easier to scoop the rice into your right hand.

tuna mayo onigiri recipe

4. Put some of your tuna mayo mixture into the divot your created. Gently enclose the rice ball around the filling. Don’t put too much filling, or else it will be difficult to close the ball.

tuna mayo onigiri recipe

You can now mold the onigiri into any shape of your choosing. (see triangle method below)

Step 4a (optional) – Onigiri triangle shaping method

Shaping your onigiri into that classic triangle shape is the most difficult part. I usually just mold my onigiri into a ball, because it’s much easier (just like making a snowball). If you really want that classic triangle look, then here’s how you do it.

  1. Cup your rice ball in your left hand. Always keep your left hand at the bottom of the onigiri. This forms the flat side of the triangle. (if you’re left-handed, you can use your right hand at the bottom instead)
  2. Use your right hand on top to gently press down and squeeze to shape one ‘point’ of the triangle. You should now have a very vague looking triangle.
  3. Rotate your onigiri 90 degrees, and use your right hand to gently mold the next point of the triangle. Rotate 90 degrees again to mold the last point.
  4. Continue to rotate and mold each point 3-5 times until you have a beautiful triangle onigiri. Just remember to keep your left hand on the bottom to form the flat side of the triangle, and your right hand on top to form the point.

It’s more difficult than it looks, so don’t worry if your first few onigiris don’t look quite right. It’ll still taste fine 😎. Here’s another video for reference:

Step 5: Wrap with seaweed (optional)

There are many ways to wrap an onigiri in nori (i.e. dried seaweed). You can cut your nori sheet into strips and wrap it around the rice ball (like the image below). You could also just wrap an entire sheet around the ball. If you don’t like nori, or can’t find any where you are, you could also choose not to wrap it at all!

The choice is yours.

tuna mayo onigiri recipe

Step 6: Enjoy

Don’t forget to eat your tuna mayo onigiri. You can put it in your lunchbox, or just stuff it in your pocket for a quick on the go snack.

tuna mayo onigiri recipe
Mmm.. jelly filled donuts

Notes and other interesting stuff about onigiri

  • Some people say to dip your hands in ICE COLD water when making onigiri, so that you can put the fresh, steaming hot rice directly on your hands. I think it’s easier to just let the rice cool down a bit.
  • Besides tuna mayo, some other common/popular flavours of onigiri in Japan are salmon, umeboshi (i.e. pickled plum), kombu (i.e. seaweed), okaka (soy sauce bonito flakes), various types of fish roe (i.e. tarako, mentaiko, etc.), and siomusubi (i.e. plain ol’ salt).
  • Another popular variation is yaki-onigiri (i.e. grilled rice balls).
  • If you really get into making onigiri, there are tons of molds you can buy to make the job a bit easier. You can even get heart shaped ones, Hello Kitty ones, and more …
tuna mayo onigiri recipe
e.g.: crazy panda onigiri maker set (from Bento & Co)
  • 7-Eleven Japan is the leading innovator on onigiri packaging
  • The first evidence of rice balls in Japan dates back to the 1st century (1-100 AD). The first recorded/written history of onigiri in Japan was from around 720 AD.
  • Another way to say onigiri is omusubi (おむすび)
  • There is an official “onigiri society” in Japan that promotes the awesomeness of onigiri. Check them out at https://www.onigiri.or.jp/onigirisociety , or on their instagram .

Conclusion

Congratulations! You can now make onigiri — one of the most classic, and popular Japanese foods of all time.

Use this tuna mayo onigiri recipe, and adapt it with your own choice of fillings and seasoning. One simple variation of tuna + mayo, is tuna + mayo + kimchi 😍.

Keep practising your triangle shaping technique, and you’ll be an onigiri master in no time.

What’s your favourite type of onigiri? Let me know in the comments!

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