Cook the rice as stated on the package.
Drain, stir the vinegar and let cool.
Cut cucumber into fine bars and salmon into strips.
Take your mat, open and put a Nori sheet on it.
Divide the rice into 4 portions and divide 1 portion as evenly as possible, so that you have covered ¾ of the norivel, the uncovered piece is at the top.
Place the salmon and cucumber in the middle of the lane strip, evenly from left to right.
Now roll up, tighten well with the mat, let it rest for 1 minute and place on a plate.
Continue with the rest.
Cut each roll into 8 pieces with a wet, sharp knife.
Serve with the soy and imposed ginger.
If you have any cucumber left, chop finely and definitely serve it.