Tuna Mayo Onigiri Japanese Rice Balls (Print Version)

Traditional Japanese rice balls stuffed with creamy tuna mayonnaise filling. Easy handheld snack perfect for lunchboxes and on-the-go eating.

# What You'll Need:

→ Rice

01 - 2 cups Japanese short-grain rice
02 - 2½ cups water

→ Filling

03 - 1 can (5 oz) tuna in water, drained
04 - 3 tablespoons Japanese mayonnaise (e.g., Kewpie)
05 - 1 teaspoon soy sauce
06 - ¼ teaspoon ground black pepper (optional)

→ Assembly

07 - ½ teaspoon salt
08 - 6 small sheets nori (seaweed), cut into strips

# Directions:

01 - Rinse the rice several times under cold water until the water runs clear. Drain thoroughly.
02 - Cook rice with 2½ cups water using a rice cooker or on the stovetop according to package instructions. Once cooked, let rest for 10 minutes.
03 - In a mixing bowl, combine the drained tuna, mayonnaise, soy sauce, and black pepper. Mix until creamy and well incorporated.
04 - While the rice is still warm but cool enough to handle, wet your hands with water and rub a little salt onto your palms to prevent sticking.
05 - Take about ½ cup of rice and flatten it into a round disc in your palm. Place a spoonful of tuna mayo filling in the center, then gently fold the rice over the filling and shape into a triangle or oval. Repeat with remaining rice and filling.
06 - Wrap a strip of nori around each onigiri before serving or packing into lunchboxes.

# Expert Tips:

01 -
  • The filling is outrageously simple but tastes like something from a professional kitchen, mostly thanks to Kewpie mayonnaise and its magical umami richness.
  • Shaping rice balls is oddly meditative once you get the hang of it, and the process becomes almost addictive after your third or fourth triangle.
02 -
  • Working with rice that is too cold will cause the grains to fall apart instead of sticking, so keep the rice warm and work quickly while shaping.
  • Overfilling is the most common beginner mistake, and even a small extra spoonful will split the rice wall and create a mess in your hands.
03 -
  • Regular mayonnaise works in a pinch but the flavor will be noticeably sweeter and less tangy, so add a tiny squeeze of lemon or rice vinegar to compensate.
  • Slightly dampening the nori with a quick breath before pressing it onto the rice helps it conform to the triangle shape and stick more securely.

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