You will need a bamboo sushi mat available at larger supermarkets in the world foods aisle. If you can’t find one cling film works well too.
Method
Put the sushi rice into a large saucepan with a lid. Cook according to the packet instructions. Remove from the heat, cover and allow to cool in the pan, according to the packet instructions.
To prepare the pickled ginger dressing: in a small bowl mix all the ingredients together and pour into a dipping bowl. Set aside.
To make the sushi: spread an even layer of rice over the nori sheet, shiny side down, Spread an even layer of rice over the nori, leaving a 1cm/½inch border. Drizzle with the mirin.
Arrange the beef, carrot, cucumber and pepper in a strip along the length of the rice. Run a pea-sized blob of wasabi (more if you like it really hot) along the edge of the filling. Slowly roll up the bamboo mat pressing lightly to seal.
Carefully remove the roll from the mat. Wrap in cling film and leave in a cool place, but not in the fridge. Repeat the process with the remaining ingredients
To serve, moisten a sharp knife, trim the edges then cut into 5-6 rolls. Serve with the pickled ginger dressing.