Prepare basmati rice in 1⁄2 l boiling salted water according to package instructions. Mix soy sauce with brown sugar and wasabi.
Drain ginger well in a sieve. Wash, clean and finely dice the cucumber. Rinse salmon, dab dry, cut into slightly wider strips. Halve avocado, remove core. Remove the flesh from the skin, cut into slices, sprinkle with lime juice.
Drain rice and stir in rice vinegar. Arrange rice, cucumber, ginger, avocado and salmon in bowls. Sprinkle with sesame seeds. Serve with sauce in bowls.