Wash 2 cups (400g) medium grain rice until
the water runs clear, then place in a saucepan with 625ml water. Bring
to the boil, then cover with a tight fitting lid, turn the heat down to
very low and cook for 15 minutes. Mix 3 1/2 tbsp rice wine vinegar. 2
tbsp mirin, 2 tsp sugar and 1/2 tsp salt in a small bowl. Pour over the
rice and fluff with a fork to separate the grains. Fold in 1 sheet
finely shredded nori and 1 tbsp chopped pickled ginger.