1. Place bamboo mat on a board or other dry flat surface.
2. Place half a sheet of nori on the mat, rough side up, one edge of the nori lining up with the front edge of the mat.
3. Dip your right fingers into the vinegar water. With damp fingers, take sushi rice and spread evenly over 2⁄3 of the nori, leaving a space at the back edge. With your right index finger, draw a line of wasabi along the rice. Place strips of cucumber side by side along the wasabi line.
4. Using both hands, lift the front edge of the mat and roll up to the end of the rice. While still wrapped, gently shape the roll, pushing rice in at both ends with fingertips. Keep lifting up front edge of the bamboo mat as you roll the sushi on to the remaining uncovered portion of nori, giving a final light press on the edge before removing the mat completely. With a wet knife, slice the roll in half, then into thirds.5. Serve with pickled ginger garnish and a dipping dish of soy sauce.
Spread rice with wet fingers, but do not splash nori.
For your first attempts at making sushi, keep fillings to a minimum for ease of rolling.For more variety, you can make more sushi using other suitable fillings such as cooked carrot sticks and asparagus.