Name: Spicy Tuna Onigiri Recipe
Prep time: 20 min
Cook time: 15 min
Total time: 35 min
Ingredients: 2 cups uncooked short grain Japanese rice; 2 1/4 cups water; 2 tablespoons rice vinegar; 1 tablespoon sugar; 1 teaspoon fine sea salt; 2 cans tuna in water (5 ounces each), well drained; 3-4 tablespoons Japanese mayonnaise; 1-2 tablespoons sriracha or other chili sauce; 1 teaspoon soy sauce; 1 teaspoon toasted sesame oil; 1 green onion, thinly sliced; 1 teaspoon lemon juice or rice vinegar; 1 tablespoon finely minced cucumber or celery; 3-4 full sheets nori, cut into strips or rectangles; 1 tablespoon toasted sesame seeds, white or black; extra salt for seasoning your hands

Spicy Tuna Onigiri Recipe tastes like a sushi roll’s fun cousin: creamy, spicy, salty, and perfectly snackable in a portable rice triangle. It works for busy folks who want a quick lunch, meal prep fans, and anyone who loves sushi flavors in about 35 minutes total. I ate an embarrassing number of these while testing, so you can trust the process.

Why Spicy Tuna Onigiri Recipe Is Worth It

This Spicy Tuna Onigiri Recipe gives you all the flavor of a spicy tuna roll without the price tag or the fuss. You get tender rice, a creamy tuna filling, and a little crunch from green onions in every bite.

It packs easily for work or school, stays tasty at room temp for a few hours, and uses simple pantry ingredients. If you can stir, shape, and resist eating the filling with a spoon, you can handle this recipe.

“This Spicy Tuna Onigiri Recipe tastes like takeout sushi in lunchbox form, and it disappears from my fridge faster than any other snack ★★★★★”

Ingredients You Need

Rice and Seasoning

2 cups uncooked short grain Japanese rice
- Use sushi rice or Calrose rice for the best stickiness.
2 1/4 cups water
2 tablespoons rice vinegar
1 tablespoon sugar
1 teaspoon fine sea salt

Spicy Tuna Filling

2 cans tuna in water, 5 ounces each, well drained
- I prefer solid or chunk light tuna for better texture.
3 to 4 tablespoons Japanese mayonnaise
- Kewpie tastes best, but any real mayo works in a pinch.
1 to 2 tablespoons sriracha or other chili sauce
- Adjust to your heat tolerance.
1 teaspoon soy sauce
- Use low sodium if you watch your salt.
1 teaspoon toasted sesame oil
1 green onion, thinly sliced
1 teaspoon lemon juice or rice vinegar
1 tablespoon finely minced cucumber or celery
- This adds crunch and freshness, optional but nice.

Nori and Finish

3 to 4 full sheets nori, cut into strips or rectangles
- Use roasted seaweed labeled for sushi or onigiri.
1 tablespoon toasted sesame seeds, white or black
Extra salt for seasoning your hands

Equipment

Rice cooker or medium saucepan with lid
Medium mixing bowl
Small bowl for hand dipping water and salt
Cutting board
Knife or kitchen scissors for nori
Plastic wrap or onigiri mold, optional but helpful

Quick Tips & substitutions

Rinse the rice until the water runs almost clear to keep the grains fluffy and not gummy.
Use canned salmon instead of tuna if you prefer a richer flavor.
Swap Japanese mayo with regular mayo plus a tiny pinch of sugar for a closer taste.
Use tamari or coconut aminos instead of soy sauce for a gluten free version.
Add more sriracha slowly and taste as you go so you do not torch your taste buds.
Wet your hands lightly and add a pinch of salt before shaping to keep rice from sticking and to season the outside.
Use plastic wrap to shape if the rice feels too hot or sticky to handle.
Pack the rice firmly around the filling so the onigiri holds together in your lunchbox.

How to Make Spicy Tuna Onigiri Recipe

Cook and Season the Rice

Rinse the rice in a bowl of cold water and swirl it with your hand.
Drain and repeat until the water looks mostly clear, then drain well.
Add the rice and 2 1/4 cups water to a rice cooker or saucepan.
Cook according to your rice cooker instructions or bring to a boil on the stove, then cover and simmer on low for about 15 minutes.
Turn off the heat and let the rice sit covered for 10 minutes so the steam finishes the cooking.
In a small bowl, stir together rice vinegar, sugar, and salt until the sugar dissolves.
Transfer the hot rice to a wide bowl and gently fluff with a rice paddle or spatula.
Drizzle the vinegar mixture over the rice and fold it in with slicing motions so you do not mash the grains.
Let the seasoned rice cool until warm but not hot, about 10 to 15 minutes.

Mix the Spicy Tuna Filling

Add drained tuna to a medium bowl and break it into small flakes with a fork.
Stir in Japanese mayo, sriracha, soy sauce, sesame oil, lemon juice, and minced cucumber or celery.
Add green onion and sesame seeds, then mix until the filling looks creamy and evenly combined.
Taste and adjust salt, soy sauce, or sriracha to match your preference.
Chill the filling in the fridge while the rice cools so it firms up a bit.

Shape the Onigiri by Hand

Set up a small bowl of water and a tiny dish of salt near your rice.
Wet your hands lightly, tap off excess water, then rub a pinch of salt between your palms.
Scoop about 1/3 to 1/2 cup of warm rice into one hand and flatten it gently into a thick disk.
Add about 1 to 1 1/2 tablespoons of spicy tuna filling in the center.
Add another spoonful of rice on top to cover the filling.
Cup your hands around the rice and gently press to seal the filling inside.
Shape the rice into a triangle by pressing with your palms and fingers, turning it as you go.
Press firmly enough to hold together but not so hard that you crush the grains.
Repeat with the remaining rice and filling, wetting and salting your hands as needed.

Add Nori and Finish

Cut nori sheets into strips or rectangles that fit around the base or back of each onigiri.
Wrap a strip of nori around the bottom or one side of each rice triangle.
Press lightly so the nori sticks to the warm rice.
Sprinkle extra sesame seeds on top if you like a little extra crunch.
Serve right away or pack in a lunch container once they cool to room temperature.

Recipe Variations

Gluten free: Use gluten free soy sauce or tamari and check your sriracha label.
Dairy free: Use a dairy free mayo that tastes neutral and creamy.
Vegan: Swap tuna with mashed chickpeas or mashed firm tofu plus a bit more soy sauce and nori flakes.
Low carb: Use cauliflower rice that you steam and mix with a bit of mayo to help it stick, then handle gently.
Extra spicy: Add chopped fresh chili or a pinch of chili flakes to the filling.
Kid friendly: Reduce or skip sriracha and add a touch more mayo for a milder filling.
Protein boost: Mix in a spoonful of Greek style dairy free yogurt or extra tofu to the filling.

Ways to Serve

Pack in a bento box with sliced cucumbers, carrot sticks, and edamame.
Serve as a quick lunch with miso soup and a simple salad.
Offer as a snack platter with cut fruit and roasted seaweed snacks.
Add to a picnic spread with other finger foods like veggie sticks and hummus.
Serve as a grab and go breakfast when you want something savory and filling.

Storage Success

Keep leftover Spicy Tuna Onigiri Recipe in an airtight container in the fridge and eat it within 1 to 2 days for the best taste and texture. Wrap each rice ball tightly in plastic wrap or parchment so the rice does not dry out and the tuna stays tucked inside. Add the nori right before eating if you want it crisp, since it softens in the fridge. If the rice feels a bit firm from chilling, let the onigiri sit at room temperature for 15 to 20 minutes before you dig in.