In a saucepan, combine the rice and water and bring to the boil. Reduce heat and leave to simmer for 15 minutes or until all the water is absorbed.
Remove from the heat, drain off any excess water and pour in the vinegar. Season with the salt. Leave aside to cool.
While the rice is cooking, peel and slice the avocado.
Lay your nori wraps onto a clean surface.
Spoon a tbsp of the rice onto each wrap. Make sure you leave about an inch at the end free of rice.
Lay your avocado slices on top and roll your wraps. Continue until all the rice and avocado have been used up.