Name: Tuna Mayo Onigiri (Japanese Rice Ball with Tuna)
Cook time: 25 min
Ingredients: 28-30 oz cooked Japanese short-grain rice (sushi rice ); 1 canned tuna (drained ); 2 Tbsp mayonnaise; 1/4 tsp soy sauce; 2 sheets full-sized nori (seaweed) (cut into 4 strips each ); sea salt

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Tuna Mayo Onigiri is one of the most popular onigiri and also one of the most loved Japanese convenience store (conbini) foods. Made with just a few pantry staples, this creamy tuna and mayo filling tucked inside warm rice and wrapped with nori is easy to prepare at home. It’s the perfect grab-and-go option for lunch, snack, or even a light meal that everyone in the family will enjoy.

Tuna mayo onigiri arranged in a bamboo rattan box.

Cooking Time: 25 minutes

Ingredients (4 servings/ 8 onigiris)

About 800–850 g / 28–30 oz cooked Japanese short grain rice
1 canned tuna (5 oz / 142g), drained
2 Tbs Mayo
¼ teaspoon soy sauce
2 full-sized sheet of nori (seaweed paper)
Sea salt (as you like for seasoning)

Ingredients for tuna mayo onigiri: cooked Japanese rice, tuna can, mayonnaise, nori sheets, salt and soy sauce.

Step-By-Step Instructions

Step 1: First, cut each nori sheet into 4 strips and set aside.

A full-sized sheet of nori seaweed before cutting.

One full-sized sheet of nori cut into four strips.

Step 2: In a mixing bowl, combine the drained tuna, mayonnaise, and soy sauce. Then, mix until well combined.

Tuna mixed with mayonnaise in a small bowl.

Soy sauce being added to the bowl of tuna and mayo.

Step 3: Next, place a sheet of plastic wrap on a cutting board and sprinkle a pinch of salt on top. After that, spread cooked rice on the plastic wrap into a rectangle (about 6 x 3 inches).

Step 4: Place about 1 tablespoon of the tuna mixture on the top half of the rice rectangle. Then, fold the bottom half of the rice over the tuna to sandwich the filling.

Tuna mixture placed on the top half of the rice rectangle.

Bottom half of the rice folded over the tuna to sandwich the filling.

Step 5: Using the plastic wrap, gently shape the rice into a triangle. Rotate and repeat with the other sides so it forms a firm triangle.

Rice being shaped into a triangle with both hands over plastic wrap.

Rice rotated while forming the triangle shape.

Step 6: Finally, remove the plastic wrap, wrap a strip of nori around the rice triangle. Then, press gently to stick it to the rice. Repeat with remaining rice and tuna mixture.

Plastic wrap removed and a nori strip being applied to the onigiri.

Nori strip wrapped around the rice ball.

Two tuna mayo onigiri served on a small plate with edamame.

RECIPE TIP

Always use rice while it’s still warm — this helps it stick together nicely and makes shaping much easier. If you’re using cold or frozen rice, just warm it up first.

Try not to overfill your onigiri. A little filling goes a long way, and keeping it light makes it much easier to form neat triangles.

For the nori, it’s all about preference! If you like that crispy crunch, wrap it right before eating. If you’re like me and don’t mind softer, moist nori, wrap it ahead of time.

Print Recipe

Tuna Mayo Onigiri (Japanese Rice Ball with Tuna)

Tuna Mayo Onigiri: a simple Japanese rice ball with creamy tuna, wrapped in nori—perfect for lunch or a quick snack.”

Cook Time25

Servings: 8 onigiris

Cost: 7

Ingredients

28-30 oz cooked Japanese short-grain rice sushi rice
1 canned tuna drained
2 tablespoon mayonnaise
¼ teaspoon soy sauce
2 sheets full-sized nori (seaweed) cut into 4 strips each
sea salt

Instructions

Cut each nori sheet into 4 strips and set aside.
In a mixing bowl, combine the drained tuna, mayonnaise, and soy sauce. Mix until smooth and well combined.
Next, place a sheet of plastic wrap on a cutting board and sprinkle a pinch of salt on top. After that, spread cooked rice on the plastic wrap into a rectangle (about 6 x 3 inches).
Place about 1 tablespoon of the tuna mixture on the top half of the rice rectangle. Then, fold the bottom half of the rice over the tuna to sandwich the filling.
Using the plastic wrap, gently shape the rice into a triangle. Rotate and repeat with the other sides so it forms a firm triangle.
Finally wrap a strip of nori around the rice triangle. Then, press gently to stick it to the rice. Repeat with remaining rice and tuna mixture.