Onigiri Rice Balls with Umeboshi Filling

By , Test Kitchen Director · Reviewed by AislePrompt Editorial · ·

Compact and flavorful rice balls filled with tart umeboshi plum paste, wrapped in nori, perfect for a convenient and authentic Japanese lunch treat. This Japanese-inspired quick recipe, ready in about 50 minutes, pairs Japanese short-grain rice uncooked, water, salt for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 250 calories and feeds 2, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Prep: 30 min Cook: 20 min Serves 2 Japanese cuisine 250 cal/serving
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Ingredients

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Instructions

  1. Step 1: Rinse 1 cup Japanese short-grain rice under cold water until water runs clear; combine with 1 1/4 cups water in a rice cooker or pot and cook according to instructions until tender and sticky, about 20 minutes; let cool slightly.
  2. Step 2: Wet your hands with water and rub 1/2 tsp salt on palms; take about 1/3 cup warm rice and flatten slightly in your palm.
  3. Step 3: Place 1 tsp umeboshi paste in the center of the rice, then mold rice around filling into a compact triangular shape, pressing gently but firmly.
  4. Step 4: Wrap the base of each rice ball with a 1-inch wide strip of nori seaweed to hold shape and add flavor.
  5. Step 5: Sprinkle 1 tbsp toasted sesame seeds over the onigiri for extra aroma and texture; pack two onigiri in a lunchbox for a portable Japanese snack or meal.

Frequently asked questions

How long does Onigiri Rice Balls with Umeboshi Filling take to make?

Total time is about 50 minutes (30 min prep + 20 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Onigiri Rice Balls with Umeboshi Filling?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep water from drying out.

Can I substitute ingredients in Onigiri Rice Balls with Umeboshi Filling?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Onigiri Rice Balls with Umeboshi Filling for a different number of people?

The recipe is written for 2 servings. Multiply each ingredient by (your serving target / 2). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

What goes well with Onigiri Rice Balls with Umeboshi Filling?

Japanese quick meals like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.

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