Tuna Recipe

Prepare tuna

Open the cans of tuna and drain thoroughly. Transfer tuna to a medium mixing bowl and use a fork to flake it into small pieces, pressing out any excess liquid.

Chop pickles

Finely chop the takuan (pickled daikon) into roughly 2–3 mm pieces so they distribute evenly in the filling and give a crunchy pickled bite.

Combine filling ingredients: add Japanese mayonnaise, chopped takuan, soy sauce, rice vinegar, toasted sesame oil, and sugar to the flaked tuna. Mix thoroughly until uniform. Season with freshly ground black pepper to taste. Taste and adjust: add a little more mayo for creaminess, more takuan for tang/crunch, or a pinch more sugar if the pickles are very salty. The filling should be cohesive but not runny — aim for about 1 to 1.5 tablespoons of filling per onigiri.

Cover the filling and refrigerate if not using immediately. The filling is best used at cool or room temperature; if chilled, let sit a few minutes to lose the chill before filling rice so it doesn’t cool rice excessively.

Rinse the rice

Place the short-grain rice in a bowl and fill with cold water. Swirl gently, drain the cloudy water, and repeat 3–4 times until the water runs mostly clear. Drain the rice well.

Soak and cook

Add rinsed rice and 420 ml water to a rice cooker or heavy-bottomed pot. Let rice soak 20–30 minutes at room temperature (important for even texture). Cook according to your rice cooker instructions, or bring pot to a gentle boil, reduce to low, cover and cook 12–14 minutes, then remove from heat and let steam, covered, 10 minutes.

Season and cool rice

Transfer cooked rice to a large bowl or hangiri. Gently fluff with a rice paddle or spatula. While still warm, sprinkle 1/4 to 1/2 tsp of the fine salt over the rice and fold gently to distribute. Let the rice cool until warm to the touch (not hot) — about 10–15 minutes — so it’s easy to shape and won’t make mayo filling overly warm.

Prepare shaping station

Set a small bowl of water at the station and add the remaining salt to it (dissolve). This salted water is for wetting your hands to prevent rice sticking and to lightly salt the outside of each onigiri. Lay out nori sheets or strips and have a spoon/portioner ready for the filling.

Shape onigiri (triangle method)

Wet your hands in the salted water, shake off excess but keep hands damp. Take roughly 1/2 cup (about 90 g) of warm rice in your hand and press into a flat oval-shaped pat. Place 1 to 1.5 tbs (adjust to taste) of the tuna pickled mayo filling in the center. Fold the rice over the filling to enclose it, then gently press and shape into a compact triangle or oval with a firm but not crushed grip. Repeat for remaining rice and filling to make about 6 onigiri.

Finish and serve

Wrap the base of each onigiri with a nori strip or a partial sheet (if preferred, wrap just before serving to keep nori crisp). Optionally sprinkle sesame seeds or a pinch of furikake on the exterior for extra flavor. Serve immediately while rice is still warm/room temperature. Store any unused filling refrigerated and use within 24–48 hours; assembled onigiri are best eaten same day.