Onigiri are just rice balls. They are a staple in Japan and there is nothing magical about them but they are delicious. The simplest version is rice, salt or maybe miso and a little seaweed as wrapper, but even that is optional. I like to put in some tasty filling. If you want to know more you should definitely read Makiko Itoh’s article.
Japanese-style vegan gluten-free 30-minutes • 850 kcal per person 
Ingredients
For two people:
- Japanese rice (japonica). This is an essential ingredient, both the texture and the taste will be quite different if you substitute a different type of rice. I use Yumenishiki, which is grown in Italy. 200 g is enough for 6 onigiri.
- Nori seaweed, the same as used for sushi. One and a half sheet of seaweed (a full standard-size sheet is 19 cm x 21 cm) is enough, cut lengthwise into six strips.
For the fillings, I used:
- 1 umeboshi (pickled japanese plum) with the stone removed, or a similar amount umeboshi paste
- hijiki seaweed with ponzu, a handful dried, soak in hot water for 30 minutes, then marinate in ponzu for another 30 minutes.
- kombu seaweed cut in strips or spaghetti seaweed with ponzu, a handful dried, soak in hot water for 30 minutes, then marinate in ponzu for another 30 minutes.
- ponzu is a mixture of
- 2 tablespoons soy sauce;
- 1 tablespoon yuzu juice, a typical Japanese citrus fruit;
- half a tablespoon rice vinegar;
- 1 teaspoon mirin rice wine You can also buy it pre-made in asian stores; you can approximate yuzu juice with lemon and tangerine, and another type of vinegar will work fine as well. Mirin adds sweetness, another sweet cooking wine would work too.
In addition to the onigiri I serve a few small dishes:
- silken tofu (200 g) with fresh ginger and some of the prepared kombu or hijiki from above
- soaked or fresh shiitake mushrooms (I cook the fresh ones for a few minutes in the microwave at full power)
- two small aubergines (400 g) with ponzu as in this recipe
Preparation
- Soak the seaweed in hot water for 30 minutes (it gets about 5x larger so use a large enough container and plenty of water).
- If it’s kombu, cut into narrow strips after soaking.
- Make the ponzu and marinate the seaweed in the ponzu for 30 minutes.
- Cook the rice as explained here.
- Wash the aubergines, slice them and cook them in the microwave for 7 minutes at full power (900 W).
- The pros shape the onigiri by hand, while the rice is still scalding hot, as explained in Makiko Itoh’s article. But I cheat and use plastic moulds for the onigiri, like these. Put the seaweed in them, then half of the rice, then the filling, then the rest of the rice. Close the mould and press. Open and shake the onigiri out. If you don’t have such moulds, then Makiko Itoh’s article shows a good way to do it without burning your hands.