Kombu Onigiri (昆布おにぎり, kelp-tsukudani rice ball)

Ingredients

Equipment Needed

• •Rice cooker or heavy lidded pot
• •Fine-mesh strainer lined with a clean cloth
• •Wooden drop-lid (otoshibuta), or a circle of parchment
• •Rice paddle (shamoji), or a broad wooden spoon
• •Onigiri mold, optional

Instructions

1. 1

   Wash the rice

   Put the rice in a bowl, cover with cold water, stir with your fingers, and pour the cloudy water away. Repeat until the water is almost clear, then soak the rice for 20 minutes and drain it for 10. Washing removes loose surface starch so the grains cling cleanly instead of turning pasty, and soaking lets the center cook through without making the outside too soft.

   Use Japanese short-grain rice. Long-grain rice will not gather properly in your hands, no matter how sternly you look at it.
2. 2

   Steep the kombu

   Wipe the kombu with a damp cloth, but don't wash it. Put it in 3 cups cold water and bring it up slowly over low heat. Pull the kombu just before the water boils, when small bubbles climb the sides and the surface begins to tremble. Boil it and the liquid turns a little slick and bitter, and the kelp loses the clean flavor you want in the filling.

   If using dried shiitake for a meatless dashi, soak it with the kombu for 30 minutes before heating. That is the way temple kitchens do it, honmono, not a compromise.
3. 3

   Finish the dashi

   Bring the water to a gentle boil, add the katsuobushi all at once, take the pot off the heat, and leave it alone for 2 to 3 minutes. The flakes will sink as they give up their flavor. Strain through a cloth and let it drip without pressing. Reserve the softened kombu and 1/2 cup of the dashi for the tsukudani; save the rest for soup.

   Don't squeeze the flakes. Pressing them forces stronger, oilier flavors into the stock, and clarity was the whole reason you handled the kombu gently.
4. 4

   Cut the kombu

   Let the kombu cool enough to handle, pat it dry, stack it neatly, and slice it into thin strips about 3cm long. This cut is not ornament. Thin strips let the seasoning reach the kelp and make the filling tender between the teeth instead of rubbery.

5. 5

   Simmer the tsukudani

   Put the sliced kombu, reserved 1/2 cup dashi, shōyu, mirin, sake, sugar, and rice vinegar in a small wide pan. Bring to a quiet simmer, cover with a wooden drop-lid (otoshibuta) or a circle of parchment, and cook for 20 to 25 minutes. Remove the lid and reduce until the liquid is gone except for a glossy coat on the kelp. Stir in the sesame seeds if using, then cool completely.

   The rice vinegar helps the kelp yield without making the filling taste sour. The final reduction matters most: loose sauce makes loose onigiri.
6. 6

   Cook the rice

   Cook the soaked, drained rice with 400ml cold water in a heavy lidded pot, or use the 2-cup line of a rice cooker. For a pot, bring it to a boil, cover tightly, lower the heat, cook 12 minutes, then rest off the heat for 10 minutes before opening. Resting lets the moisture settle evenly, which gives you rice that shapes without smearing.

7. 7

   Salt your hands

   Turn the rice gently with a rice paddle and let it cool only until your hands can bear it. Set out a bowl of water and the salt. Wet your palms, rub on a pinch of salt, and keep the remaining rice covered. Warm rice is pliable; cold rice cracks and resists you. The salt seasons the outside and helps the onigiri keep for the lunch cloth.

8. 8

   Fill and shape

   Scoop about 1/2 cup warm rice into one damp salted palm. Make a shallow hollow, add 1 heaping teaspoon of kombu tsukudani, cover with a little more rice, and press lightly into a triangle or round ball. Use enough pressure that it holds, then stop. Too much turns a rice ball into a rice brick, and we have enough bricks in the world.

9. 9

   Wrap and serve

   Wrap each onigiri with a strip of nori just before eating, or pack the nori separately for a picnic. If making ahead, let the onigiri cool on a plate until the surface no longer feels damp, then wrap each one individually and keep cool. Eat them the same day. The filling is sturdy, but cooked rice still asks for respect.

Chef Tips

• •The best kombu for this is not necessarily the grandest piece in the shop. Medium-thick stock kombu, especially after making dashi, gives you a filling with body and chew. Very thick kombu may need another 10 minutes in the pan.
• •Reduce the tsukudani until it shines but does not run. That is the first secret here. Wet filling loosens the rice, and no amount of hand-shaping fixes that later.
• •Real mirin gives round sweetness and gloss. If yours tastes like syrup and salt, use a little more sake and a little less sugar instead of pretending the bottle is doing the same work.
• •For a meatless table, use kombu and dried shiitake dashi. It belongs to the tradition, and the kombu filling stays the center of the dish.
• •Wrap nori at the last moment if you like it crisp. Wrap it earlier if you like it soft against the rice. Both are eaten in Japan; just know which texture you're choosing.

Advance Preparation

• •The kombu tsukudani can be made up to 1 week ahead and kept refrigerated in a covered container. Bring it to room temperature before filling the rice.
• •The dashi keeps 2 days refrigerated. Save the extra for miso soup, and the onigiri suddenly has a proper small meal beside it.
• •Shape onigiri the morning you plan to eat them. For a picnic, cool them, wrap individually, pack with a cold pack, and keep the nori strips separate until serving.

Frequently Asked Questions

Nutrition Information

1 serving (about 150g)