Prepare the sushi rice. Wash the rice very well until the water runs clear, then leave to soak in fresh water for 15 mins. Drain, then put in a medium saucepan, cover with 350ml water and a generous pinch of salt, bring to the boil, then put the lid on and reduce to a low heat. Cook for 10 mins. Turn off the heat but leave the lid on the rice, and leave to stand for 15 mins.

Once the rice is cooked, stir in the sushi vinegar. Spread the rice over a plate lined with baking parchment to cool completely. Make the filling in the meantime. Mix all the ingredients together in a large bowl and season lightly with salt and pepper. Keep in the fridge until you’re ready to make the onigiri.

Use an onigiri mould if you have one. Using wet hands, smooth 3-4 tbsp rice into the larger triangle, then top with 2-3 heaped tbsp of the filling, then cover with more rice and use the smaller triangle to shape the onigiri. If you don’t have an onigiri press, form the rice balls with wet hands, using baking parchment to help shape them. Will keep for a day in the fridge.

Wrap a nori sheet around each onigiri, then chill until ready to eat or pack in a lunchbox and cool bag.