30-Minute Onigiri Recipe: Tuna Mayo, Umeboshi, and Furikake
Jennifer Miller
Onigiri are hand-shaped Japanese rice triangles wrapped in nori and filled with savory ingredients — here, creamy tuna mayo, tangy umeboshi plum, and seasoned furikake. Using warm, freshly cooked rice makes shaping straightforward and keeps the total time to about 30 minutes. The three fillings cover a range of flavors, from rich and savory to bright and pickled.
Nonstick skillet (optional, for toasting sesame or yaki-onigiri)
Cutting board and chef's knife
Plastic wrap (optional for shaping)
Kitchen towel
Ingredients
4cupscooked Japanese short-grain riceWarm; Koshihikari or Tamanishiki preferred. Use two 8.8 oz microwave pouches or leftover rice gently reheated.
1tbspunseasoned rice vinegarAvoid seasoned sushi vinegar to control salt/sugar precisely.
1tspgranulated sugar
½tspkosher saltFor seasoning the rice
1cupcold waterFor dipping hands to prevent sticking
1tspkosher saltFor the hand-dip water
1can (5 oz)tuna, well drainedJapanese-style or solid light tuna; oil- or water-packed is fine.
2tbspKewpie mayonnaiseKewpie for authentic flavor; regular mayo works in a pinch.
1tspsoy sauceLight or regular; adjust to taste.
3piecesumeboshi (pickled plum), pitted and tornLook for soft, high-quality umeboshi; adjust to your salt preference.
2tbspfurikake rice seasoningAny style you like; nori-tama or shiso flavors are great.
4sheetsroasted noriCut into 8 strips; add just before serving for maximum crispness.
2tsptoasted white sesame seedsOptional garnish
1tbspneutral oilOptional, for pan-searing yaki-onigiri
1tbspsoy sauceOptional, for brushing yaki-onigiri
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Instructions
Set up your station: In a small bowl, dissolve 1 tsp kosher salt in 1 cup cold water. This salted water prevents sticking and lightly seasons the surface of the rice. Keep a kitchen towel nearby to dab excess water from your hands.
Season the warm rice: In a medium bowl, stir together 1 tbsp rice vinegar and 1 tsp sugar until dissolved. Sprinkle evenly over 4 cups warm rice with 1/2 tsp kosher salt. Fold gently with a rice paddle using slicing motions to avoid smashing grains. The rice should look glossy and smell lightly tangy.
Mix tuna filling: In a separate small bowl, combine drained tuna with 2 tbsp Kewpie mayo and 1 tsp soy sauce. It should be creamy but not soupy. Taste and adjust with a pinch of salt if needed.
Prep other fillings: Pit and tear 3 umeboshi into bite-size pieces. Set out 2 tbsp furikake. Cut 4 nori sheets into 8 strips (half-sheets).
Optional toasting: Toast sesame seeds in a dry nonstick skillet over medium-low heat (about 300°F/150°C surface temperature) for 2–3 minutes, shaking until fragrant. Transfer to a dish to cool.
Shape the onigiri: Dip clean hands into the salted water and shake off excess. Scoop about 1/2 cup rice into your palm. Make a small well, add about 1 tbsp of a filling (tuna, umeboshi, or a heavy sprinkle of furikake), then cover with a little rice. Using gentle three-sided presses, form a triangle: press the edges with your fingertips, rotating as you go. The onigiri should be compact, not crushed—surface slightly tacky, edges neat.
Wrap and garnish: Press each onigiri lightly into sesame seeds if using. Wrap with a strip of nori just before serving so it stays crisp. For furikake onigiri, roll the triangle lightly in furikake or sprinkle on the outside.
Optional yaki-onigiri (pan-seared): Heat 1 tbsp neutral oil in a nonstick skillet over medium heat (about 350°F/175°C surface temperature). Brush both sides of an onigiri with a little soy sauce and sear 30–45 seconds per side until lightly caramelized. Add nori after searing to preserve crispness.
Notes
Jen’s Tips
Rice temperature: Warm (not hot) rice is easiest to shape; too hot and it steams the nori limp, too cold and it won’t stick together.
Hand water vs. plastic wrap: If you prefer mess-free shaping, place rice on a sheet of plastic wrap, add filling, wrap and mold, then unwrap and add nori.
Season balance: Rice should taste gently savory-sweet with a whisper of vinegar—adjust sugar or salt by 1/8 tsp at a time.
Substitutions: Use vegan mayo with mashed chickpeas for a plant-based “tuna” filling; swap umeboshi with quick-pickled chopped cranberries for a playful tart note.
Furikake variety: Try shiso furikake for a floral, minty lift or wasabi furikake for heat.
Nori timing: Always add nori at the last moment for maximum crunch—especially if packing for lunch, keep it separate to wrap just before eating.
Serving Suggestions
Plate three onigiri—one of each flavor—on a slate or light-colored plate for contrast. Stand them upright to showcase the clean triangle edges and the dark nori band. Garnish the plate with a sprinkle of sesame seeds and thin-sliced scallions. Serve with a small bowl of miso soup or chilled green tea. Perfect onigiri look satin-glossy, hold their shape, and release a gentle aroma of vinegar and seaweed when picked up.
Culinary Context
Onigiri have been cherished in Japan for centuries as the ultimate travel food—simple, sturdy, and comforting. From samurai provisions to modern convenience-store artistry, their magic lies in the interplay of well-seasoned rice and a small but punchy filling. My version honors that heritage while streamlining the process for weeknights.
Optional Advanced Instructions
Cook rice from scratch (make-ahead): Rinse 1 1/2 cups uncooked short-grain rice until water runs mostly clear. Cook with 1 3/4 cups water: bring to a gentle boil, cover, and simmer 12 minutes; rest 10 minutes off heat. Fold in vinegar/sugar/salt while warm. This adds ~20 minutes but can be done ahead and rewarmed gently.
Batch and freeze: Shape plain triangles and freeze. Reheat wrapped in a damp paper towel in the microwave until warm, then add nori and seasonings.
Beginner alternative: Use a triangle mold for consistent shapes; lightly dampen the mold and pack gently to avoid dense rice.
Timing
Prep Time: 0 hours 20 minutes
Cook Time: 0 hours 5 minutes
Total Time: 0 hours 25 minutes
Course & Origin
Course: Lunch
Cuisine: Japanese
Origin: Japan
Yield is about 8 onigiri (2 per person). Keep nori separate if packing for later, and wrap just before eating to maintain its crisp snap.