1 Rinse sushi rice with cold water in a sieve until the water runs clear. Drain for about 20 minutes, then transfer to a pot with 250 ml (approximately 1 cup) of water and bring to a boil.
2 Cook uncovered for 2 minutes, then covered for another 20 minutes. Remove the pot from heat, remove lid and cover with a kitchen towel. Let rice stand for 10 minutes.
3 In a small pot, combine 1 1/2 tablespoons rice vinegar and mirin with sugar and salt and cook at medium-high heat, stirring until sugar and salt have dissolved. Place the rice in a bowl and spread slightly to speed cooling. Pour the vinegar mixture onto rice and allow to cool to room temperature for about 30 minutes.
4 Wrap a bamboo sushi mat with plastic wrap.
5 Rinse salmon, pat dry and cut into small finger-sized pieces.
6 Halve avocado, remove pit and remove the fruit by gently working the spoon between the flesh and skin. Cut into thin slices and sprinkle with remaining rice vinegar to prevent discoloration.
7 Cut nori in half diagonally.
8 Laying 1/2 sheet of nori on the mat, spread 1/4 of the rice mixture evenly on top, pressing firmly.
9 Sprinkle some sesame seeds over the rice and invert so that rice is touching the bamboo mat sheet and nori is on top.