Tuna Mayo Onigiri is one of Japan’s most popular rice balls, often found in convenience stores and bento boxes. This creamy, umami-packed filling combines tuna, mayonnaise, soy sauce, and katsuobushi (bonito flakes) for an extra depth of flavor. Follow this easy homemade recipe to create the perfect grab-and-go Japanese snack!
Tuna Mayo Onigiri
Difficulty: ★★☆☆☆2
servings10
minutes20
minutesIngredients
- For the Rice:
3 cups (about 600g) warm cooked Japanese short-grain rice
Salt, to taste (For seasoning the rice.)
- For the Tuna Mayo Filling:
1 can (about 5 oz) tuna, drained (Oil-packed tuna for richness, or water-packed for a lighter version.)
1 tbsp Japanese mayonnaise (Kewpie recommended) (Regular mayo works, but Japanese mayo adds extra creaminess.)
1–2 tsp soy sauce (Adjust to taste.)
1 small packet of katsuobushi (bonito flakes) (optional but recommended for extra umami!)
- For Wrapping (Optional):
5–6 sheets of nori (seaweed), cut into strips
Directions
- Season the Rice
Lightly sprinkle salt over the warm rice and mix gently to distribute the seasoning.
The salt should be slightly mild, as the tuna mayo filling adds extra flavor. - Make the Tuna Mayo Filling
In a bowl, mix together drained tuna, mayonnaise, and soy sauce.
Add katsuobushi (bonito flakes) and mix again to distribute evenly.
Taste the mixture and adjust the soy sauce if needed. - Shape the Onigiri
Divide the rice into 5–6 portions.
Take one portion and make an indentation in the center.
Add about 1 tbsp of the tuna mayo mixture into the indentation.
Gently cover the filling with rice and shape into a triangle or ball using your hands or plastic wrap. - Add the Nori (Optional)
If using nori, wrap a strip of seaweed around the bottom of each onigiri for easier handling. - Serve & Enjoy!
Enjoy your homemade Japanese-style tuna mayo onigiri fresh or pack it for a bento!
Notes
- ✔ For extra umami: Add a dash of dashi powder or a few drops of sesame oil to the filling.
✔ For a crispy texture: Lightly pan-fry the onigiri with butter or sesame oil for a crunchy exterior.
✔ For meal prep: Store in plastic wrap and refrigerate. Best eaten within 24 hours.
✔ For variety: Mix in chopped green onions or black sesame seeds for extra flavor and texture.
✔ For a convenience store-style finish: Wrap each onigiri in plastic wrap and chill slightly before eating.