- Rinse the rice under cold running water and drain.
- Cook rice in water until it boils.
- Reduce to a simmer and cook until all the water is absorbed (about 10 to 12 minutes).
- Tip cooked rice into a bowl and allow to cool for 10 minutes.
- Mix vinegar and sugar and mix into the rice, set aside to cool to room temperature.
- Chop the cucumber into small sticks.
- In another bowl mix the mayonnaise with the tuna.
- Lay out your bamboo rolling mat, place a sheet of nori on the mat, shiny side down.
- Spread the rice over the nori (leaving a centimetre of empty space along the edge of the nori furthest from you)
- Place the tuna and cucumber horizontally along the roll. Roll everything up pressing firmly.
- When you reach the top 1 centimetre edge, dampen this part with water and continue rolling to seal the edge.
- Place the roll onto a chopping board and slice into 12 pieces using a sharp knife.
Try different fillings like avocado slices, carrot sticks or an egg omelette cut into strips.