Atlantic salmon
Rinse the sushi rice under cold water until the water runs clear. Cook the rice according to package instructions. Once cooked, transfer to a large bowl and let it cool slightly.
In a small bowl, mix the rice vinegar, sugar, and salt until dissolved. Pour this mixture over the warm rice and gently fold it in with a spatula. Allow the rice to cool to room temperature.
Slice the Atlantic salmon fillet and cucumber into thin strips.
Lay a nori sheet on a bamboo sushi mat, shiny side down. Wet your hands to prevent sticking, and take a handful of sushi rice, spreading it evenly over the nori, leaving about an inch at the top edge. Place a few strips of salmon and cucumber in the center of the rice.
Using the bamboo mat, carefully roll the sushi away from you, applying gentle pressure to form a tight roll. Seal the edge of the nori with a little water.
Using a sharp knife, slice the roll into 6-8 pieces. Serve with soy sauce, wasabi, and pickled ginger on the side.