These little “sandwiches” are quite delicious, with the umami-laced seeds pairing so well with the rich tuna and gently sweet rice. This is great lunchbox fare, for all ages. Fill them with pretty much anything – prawns, chicken, boiled egg or sliced omelette, tofu, marinated seaweed, Japanese pickles, vegetables or shredded shiso. Any mix of tamari-flavoured seeds and nuts works here, nut allergies notwithstanding, though sesame is a good component.
300g (1½ cups) short-grain rice
3 tbsp mirin
3 tbsp rice wine vinegar
8 nori sheets
300g sashimi-grade tuna, cut into 2cm x 8cm batons
1½ avocados, each half sliced in four
2 tbsp cooked soybeans (or 12 cooked green beans)
5 spring onions, finely sliced
1 cucumber, deseeded and julienned
3 tbsp mayonnaise
3 tbsp spiced tamari seed and nut mix, roughly ground
½ lemon, juiced
1 tsp sesame oil
1 tsp grated ginger
1. Add the rice and 2½ cups of boiling water to a medium saucepan and bring to a simmer. Wrap the saucepan lid in a tea towel and seal tightly. Cook over a low heat for 15 minutes. The water should be entirely absorbed, and the rice cooked. Stir through the mirin and vinegar, then cool to room temperature.
2. Lay a nori sheet flat on a plate and press on a palm-sized square of rice about 1cm thick. Top with tuna, avocado, soybeans (or green beans), spring onion and cucumber, then dollop on some mayonnaise and some of the spiced seed mix. Top with another palm-sized square of rice to sandwich the ingredients together, pressing a little to compact. Fold the nori over the rice and top with a second sheet, wrapping around to form a firm, square parcel with no rice showing. Repeat to make four sandwiches.
3. Wrap the sandwiches tightly in cling wrap, place between two plates to gently press together, and refrigerate for 30 minutes.
4. To make the dipping sauce, mix all the ingredients together.
5. Once chilled, cut the sandwiches in half to expose the ingredients in the middle and serve with the sauce on the side.