Japanese Tuna-Mayo Onigiri
ツナマヨおにぎり·(tsuna-mayo onigiri)
SNACKS
In 1983, a Japanese convenience store chain gambled on mixing mayonnaise into rice. It fundamentally altered the nation's fast food. The secret to this domestic wafu version is a tiny hit of tamari bridging the rich, creamy fish and the seasoned rice. It is the ultimate packable snack: deeply savory, structurally sound, and taking mere minutes of active work. If you have leftover rice, a totally flare-proof, desperately satisfying bite is less than ten minutes away.
Ingredients
- short-grain white rice2 cup
- water-packed canned tuna5 oz
- plain conventional mayonnaise2 tbsp
- tamari1 tsp
- rice vinegar1/2 tsp
- sugar or MSG1 pinch
- kosher salt1/2 tsp
- roasted nori sheets2 large
Method
- 01
Drain the tuna ruthlessly.
Press down on the lid to squeeze out as much water as physically possible. If the tuna is wet, the mayonnaise will separate and your rice ball will turn to mush.
- 02
Mix the wafu mayo.
In a small bowl, combine the violently drained tuna, mayonnaise, tamari, rice vinegar, and sugar. Flake the tuna with a fork and mix until you have a smooth, creamy paste.
- 03
Set up your station.
You cannot shape onigiri with dry hands, as the rice will stick to you like glue. Keep a small bowl of water and your kosher salt right next to your cutting board.
- 04
Shape and indent the rice.
Wet both hands thoroughly in the bowl of water, rub a pinch of salt across your palms, and scoop about a half cup of the warm rice into one hand. Flatten it slightly and use your thumb to press a shallow well into the center.
- 05
Seal the triangle.
Drop a generous tablespoon of the tuna-mayo filling into the well. Cup your hands and gently fold the edges of the rice up and over the filling, gently squeezing and rotating the rice ball until it forms a neat, firm triangle.
- 06
Wrap in seaweed.
Take a strip of nori and wrap it up from the bottom of the triangle, folding it over the sides so it sticks to the moisture of the rice. Eat immediately while the nori is crisp.
Notes
Why this swap: clean-label mayonnaise for Kewpie.
Authentic Japanese recipes swear by Kewpie mayonnaise, famous for its rich umami depth. However, commercial Kewpie formulas often list "spices" or "natural flavors" on the label, which are notorious hiding spots for high-FODMAP garlic and onion powders. We bypass the risk entirely by starting with conventional mayonnaise, doctored with rice vinegar and a pinch of sugar or MSG to perfectly mimic that sweet, tangy umami without the Wednesday-morning flare.
Why this swap: tamari for soy sauce.
Traditional wafu tuna-mayo uses standard soy sauce, which contains wheat. Tamari delivers the exact same deep, salty umami without a trace of wheat.
Non-FODMAP gut irritant warning.
This is a richer dish—for some readers, the fat content itself can be a trigger even when the FODMAP load is fine. Pair with a lighter side and a smaller portion if you're currently sensitive.
The short-grain rice rule.
You absolutely must use short-grain (japonica) rice. Long-grain rices like jasmine or basmati do not contain enough sticky amylopectin to hold together, and your onigiri will crumble the second you pick it up. If using leftover fridge rice, microwave it under a damp paper towel for a minute to resurrect the sticky starches before shaping.