Onigiri

Thoroughly rinse the rice in cold running water until the water runs clear. You will have to do this a few times to ensure the rice is properly rinsed.

Combine the rice and 500ml (2 cups) water in a saucepan. Place over a medium heat and bring to the boil, then cover and reduce the heat to low. Leave to simmer for 10–15 minutes until the water has evaporated, then turn off the heat and leave to steam for another 10–15 minutes. Alternatively, use a rice cooker.

Once the rice is ready, season it with the sushi vinegar, salt and sugar while it is still hot. Mix well with a flat rice paddle or plastic spatula to avoid breaking any grains, then transfer to a large tray. Spread it out evenly and leave to cool for 15–20 minutes.

To make the filling, combine the tuna, sweetcorn and mayonnaise in a small bowl. Mix and set aside.

When the rice has cooled, it’s time to shape the onigiri. To do this, wet your hands with a little water, then take about 115g (4oz) of the rice and gently roll it to form a ball.

Now, gently shape the ball into a triangle. Flatten the rice triangle slightly, then place 1 teaspoon of the filling in the centre, and cover it with a little more rice. Carefully press the filled rice back into a triangle shape, making sure to not expose the filling. Repeat until all the rice and filling have been used up.

To finish, wrap a strip of nori around the onigiri just before serving, and garnish the top with a sprinkling of sesame seeds.