Place a nori sheet with shuffle side down on a bamboo mat. Spread a centimeter thick layer of the cooked, cooled rice on three quarters of the sheet.
Apply a strip of filling, salmon and avocado, spread a very thin strip of wasabi paste on the fish. Moisten the free edge of the sheet with water.
Roll hard with gently folding the entire roll using the bamboo mat. Cut with sharp and moist knife into centimeter-wide pieces. Dip the sushi pieces in soy flavoured with wasabi paste.