Stay ready for last-minute snackage & meals with this easy Spicy Tuna Onigiri - no fancy wrapping required! These beginner-friendly Japanese tuna rice balls come together in 15 minutes so you never go hangry - even on the go!
These easy spicy Tuna Onigiri recipe, or Japanese rice balls usually in a triangle shape, is a popular Japanese snack. Onigiri can be easily found at Japanese convenience stores & make for the perfect budget-friendly meal. Luckily, they're also so easy to make with a few tips, the kids would enjoy making them too! Plus, they're so versatile.
Canned tuna is an easy go-to filling for homemade onigiri because it has a long shelf-life for emergency meals. You can also easily swap it out for Salmon Onigiri or even grill it up Yaki Onigiri with golden crispy rice! (Even more different fillings below!)
They're complete meals in the palm of your hand.
❤️ Recipe Highlights
- Shelf Stable Ingredients: Stay ready with last-minute snacks & meals! This Tuna Onigiri recipe is made of long shelf life ingredients that can be easily stored in the pantry so you never go hangry 😉 gotta love Pantry Staple recipes
- Portable Snack On-the-Go: Pack these up for your adventures! Road trips, weekend picnics, or even last minute lunches - no utensils required!
- Beginner-Friendly Molding: Save even more time & get these delicious onigiri in your tummy ASAP with perfect onigiri - every time.
🥘Tuna Onigiri Ingredients
- Short Grain Rice: For this Tuna Onigiri recipe, the best rice to use is short-grain rice but medium grain rice would work too! Short grain rice has a stickier consistency compared to long grain rice. You can easily find it at local Asian grocery stores, Japanese markets, or online labeled as sushi or sweet rice.
- Japanese Mayo: Japanese mayo is creamier with a subtle tang compared to American mayo. I HIGHLY recommend using it for this tuna rice ball recipe. Kewpie mayonnaise is the most popular brand & can easily be found at local Asian & Japanese markets or online. It’s becoming increasingly popular, so some local grocery stores have it in the Asian/International section.
- Soy Sauce: I like to season the filling with regular soy sauce for its saltiness & umami.
- Rice Vinegar: I like to add just a touch of rice vinegar to balance the creaminess & saltiness from the other simple ingredients.
- Sriracha: If you’re a spicy lover, add a bit (or more!) of sriracha. It’s your onigiri, so customize it to your taste buds!
- Salt: A sprinkle of salt on the rice is a traditional Japanese rice seasoning for used to season the rice, as well as help preserve the onigiri. Keep in mind, a little goes a long way - you don’t want your onigiri too salty!
- Nori Sheets: This dried nori seaweed adds flavor & also helps prevent your fingers from sticking to the onigiri while eating.
- Furikake: There are a wide variety of furikake, but the base ingredients are seaweed & sesame seeds. Feel free to experiment/use your fave kind of furikake!
See recipe card for quantities.
📖 Variations & Substitutions
Onigiri is easily customizable! If you're a spicy lover (like me!), add more sriracha. Not in the mood for tuna? No problem!
Swap out tuna for different onigiri fillings. Here are a few variation ideas:
🔪 How to Make Tuna Onigiri
Step 1: In a medium-sized bowl, combine tuna, Japanese mayo, soy sauce, sesame oil, rice vinegar, & sriracha (if using). Set aside.
Step 2: In the onigiri mold, sprinkle a pinch of salt to the bottom of the mold, then fill the mold about halfway with rice. Dip your fingers/spoon with some water to help prevent sticking & create a small divot in the center.
Step 3: Scoop about a tablespoon of the tuna filling in the center (exact amount will vary depending on size of mold), add another layer of rice to fill the mold, then sprinkle a tiny bit more salt on top.
Step 4: Cover with the mold's top & gently but firmly press down. You should feel a bit of resistance, otherwise, you may want to add a bit more rice so the onigiri is packed. Press the back of the onigiri mold to release the onigiri from the mold.
Step 5 (optional): Roll the sides of the onigiri in black sesame seeds (if using) for a little extra flavor & crunch.
Step 6: Wrap the onigiri with a nori sheet, then repeat the process for remaining rice & filling. Enjoy immediately!
👩🏽🍳 Key Tips
- Key Tip for Packing On-the-Go: If you're not planning to eat your tuna onigiri immediately, store the nori separately until you're ready to eat, otherwise, it'll become very soggy.
- Using a Mold: Using a mold makes the onigiri process so much easier! Make sure the rice & filling are really packed in the onigiri mold. This makes it much less likely to fall apart while eating.
- No Mold? No Problem! To make the tuna-mayo onigiri without a mold, went your hands with water and sprinkle & little salt in the palm of your hands. Spread a thin layer of rice in the palm of your hand, add tuna filling in the center, then wrap rice around the tuna filling into a triangle shape. Wrap in nori & enjoy.
- Wash Rice Before Cooking: It’s super important to wash the rice multiple times before cooking. This removes excess starch, which would turn your rice mushy & glutinous otherwise.
- Use Fresh Hot Rice: Hot is much stickier & the onigiri will hold its shape much better than when using cold rice.
- Prevent Rice Sticking to Your Hands: Rice, especially short grain rice, is much stickier! To make it much easier to work with, dip your hands/spoons in water before touching the rice to help prevent the rice sticking.
- Importance of Salting the Rice: Sprinkle a little salt into the bottom of the mold & again at the top. Salting the rice seasons it & is traditionally used to help preserve the onigiri, along with adding more flavor.
💭 Recipe FAQs
Japanese Tuna onigiri is best enjoyed immediately, but if you have leftovers, wrap it in plastic wrap and leave at room temperature. If possible, store onigiri without the nori, otherwise, it'll be soggy later.
The salt on the rice helps preserve the onigiri for up to 5 hours. Any more than that, store the onigiri in the fridge.
Onigiri can be enjoyed room temperature or warm, depending on your preference.
To reheat the onigiri, place the onigiri in the microwave with a damp paper towel on top to prevent the rice from drying out. Reheat until the rice is warm & tender again. Wrap in nori & enjoy!
Tuna onigiri is typically eaten at room temperature or warm, but you can eat it chilled depending on your preference.
Sushi rice is typically used for onigiri, which is a short grain rice with a stickier consistency than long grain rice. It can be easily found at local Asian or Japanese markets or online.
One of two things may be happening: Either the rice was too cold or the onigiri wasn't compressed enough.
Make sure the rice is warm when making the onigiri because it's stickier than cold rice. Then, when molding the onigiri, compress the ingredients firmly together so it's compacted. These two key tips will help the onigiri hold its shape much better!
Yes! Individually wrap onigiri in plastic wrap without the nori (it'll turn soggy otherwise) & store for up to a month.
To reheat, cover with a damp paper towel, place in the microwave, & heat until warm & the rice is tender. Wrap with nori & furikake, if using.
Onigiri is a finger food eaten like a sandwich - no utensils needed! Just pick it up & enjoy!
If you're making these Japanese rice balls to enjoy later, keep the nori/seaweed separate until you're about to eat. Wrap the spicy tuna mayo onigiri in the nori right before enjoying.
🥗 What to Eat with Tuna Onigiri
Tuna onigiri is a delicious quick snack on its own or can be enjoyed as part of a larger meal. Enjoy it with spicy garlic edamame, teriyaki salmon or chicken, or tonkatsu.
Let's Get Cooking!
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Spicy Tuna Onigiri (Japanese Tuna Rice Balls)
- In a medium-sized bowl, combine tuna, Japanese mayo, soy sauce, rice vinegar, & sriracha (if using). Set aside.
- In the onigiri mold, sprinkle a very small amount of salt, add enough rice to cover the bottom of the mold. Then, add about 1 ½ tablespoon of tuna filling in the center, then more rice on top to cover the filling. Note that the amount of rice and filling depends on the size of the mold. For best results, make sure your rice & filling are really packed in.
- Put the top of the mold on top, then gently & firmly press to make rice tightly packed. You should feel a little resistance, but if you don’t, you might want to add a bit more rice so your onigiri is full & tightly pressed together. Press the back of the mold to release the onigiri.
- Wrap onigiri with a piece of nori.
- Roll the sides of the onigiri in furikake, if using. Repeat for remaining filling & rice. Enjoy immediately!
- Short Grain Rice: Sushi rice is used for this recipe, which has a stickier consistency compared to long grain rice. You can easily find it at local Asian & Japanese markets or online.
- Japanese Mayo: I HIGHLY recommend using Japanese mayo for this recipe! It's creamier with a subtle tang & there's no going back 🙂 Find it at local Asian & Japanese markets or online & sometimes even at some local grocery stores in the Asian/International section.
- Soy Sauce: I'm using regular (not low-sodium) soy sauce for its saltiness & umami.
- Rice Vinegar: Just a touch of rice vinegar adds balance to the creaminess & saltiness from the mayo, soy sauce, & salt.
- Sriracha: This is totally optional! It's a great addition if you love spice, but again, adjust to your taste buds!
- Salt: A sprinkle of salt on the rice is traditionally used to season the rice as well as help preserve the onigiri. Keep in mind, a little goes a long way - you don’t want your onigiri too salty!
- Nori: This dried seaweed adds flavor & also helps prevent your fingers from sticking to the onigiri while eating.
- Furikake: There are a wide variety of furikake, so feel free to experiment/use your fave kind of furikake!
- Step-by-Step Photos: For key tips & step-by-step instructions with photos, please refer to the blog post above!
Exact calculations may vary. For the most accurate nutritional information, use your preferred nutrition calculator, actual ingredients, and quantities used for the recipe. Please consult with your physician or registered dietitian if more precise nutrition calculations are needed for health reasons.