3 Reduce the heat to low and cook for a further 20 minutes without removing the lid.
4 Mix together the vinegar, salt and sugar.
5 Remove the rice from the pot and spread onto a flat tray. Stir the rice continuously while sprinkling over the vinegar mixture until the rice is cool.
6 Place one sheet of nori on the sushi mat. Wet your fingers before spreading the rice - 1cm thick - over the nori, leaving a 3cm space at the far end.
7 Smear wasabi along the front edge, add a little pickled ginger and a sprinkling of soy. Add the chosen filling then roll with the sushi mat to make a tight roll, squeezing as you go.
8 Remove mat, slice rolls and arrange more of the toppings on top of each before serving.