1.In a large bowl, wash rice with cold water until water is almost clear. Drain rice in strainer at least 30 minutes.
2.To make vinegar: combine all ingredients in a small jug.
3.To make chicken teriyaki: in a small bowl, combine chicken, sauce and garlic. Heat a small frying pan over high heat. Spray with cooking oil spray for 1 second. Cook chicken, stirring, until just cooked through. Cool.
4.In a medium saucepan, bring rice and the measured water to the boil, covered tightly. Reduce heat; simmer, covered, about 30 minutes or until the water is absorbed. Remove from heat; stand, covered, 10 minutes.
5.Spread rice into a large, non-metallic, flat-bottomed bowl (a wooden bowl is good for this). Using a plastic spatula, repeatedly slice through rice at an angle to separate grains, gradually pouring in vinegar at the same time.
6.Continue to slice the rice mixture with one hand; fan the rice with the other hand about 5 minutes or until it is almost cool. Cover rice with damp cloth to stop it drying out while making sushi.
7.Add rice vinegar to a medium bowl of cold water. Place one nori sheet, shiny side down, lengthways across bamboo mat about 2cm from edge of mat closest to you. Dip fingers of one hand into bowl of vinegared water, shake off excess; pick up a third of the rice, place across centre of nori sheet.
8.Wet fingers again, then gently rake rice evenly over nori, leaving a 2cm strip on the far side of the nori uncovered. Build up rice in front of uncovered strip to form a mound, to keep filling in place.
9.Place a third of the cucumber, sprouts and chicken in a row across centre of rice, making sure the filling extends to both ends of the rice.
10.Starting with edge closest to you, pick up mat using thumb and index fingers of both hands; use remaining fingers to hold filling in place as you roll mat away from you. Roll forward, pressing gently but tightly, wrapping nori around rice and filling.
11.Working quickly, repeat process to make a total of three rolls. Cut each roll into four pieces. Serve with soy sauce and wasabi, if desired.