First, prepare your seasoned sushi rice. Put the rice into a large bowl with a little cold water and wash it thoroughly. Use your fingers to swirl the rice around in the water, adding a little more cold water as the water becomes cloudy with the rice starch. Carefully drain the water and repeat the process until the water becomes clear.
Add the rice to a small saucepan with 330 ml of cold water and pop the lid on. Bring to a boil over a high heat. As soon as the water starts boiling reduce the heat to the lowest setting you can get and simmer for ten minutes. KEEP THE LID ON.
While the rice is cooking, prepare your sushi vinegar. Combine the rice vinegar, caster sugar and salt in a small clean jam jar, pop the lid on and shake, shake, shake (get the kids to do this!). Leave the mixture to rest for 10-15 minutes.
Transfer the hot cooked rice to a bowl and carefully fold in the sushi vinegar. You don't want to break the grains of rice. Leave it to cool for 25-30 minutes.
To assemble the sushi, lay a sheet of nori seaweed shiny side down onto a Yutaka bamboo sushi rolling mat.
Spoon 1/3 of the rice mixture onto the nori seaweed and using fingers dampened with a bit of cold water, spread the rice in an even layer leaving a 1 cm gap at the top. Make sure your rice reaches the sides of the nori seaweed.
Take one piece of smoked salmon and arrange it in a line about 1/3 of the way up from the bottom of the nori. Top with a few chives and a few pieces of sliced avocado.
Using the Yutaka bamboo rolling mat to help you, fold over the bottom edge of the nori seaweed and roll into a thick cigar shape.
Using a finger dipped in cold water, moisten the edge of the nori seaweed to seal. At this point you could wrap the sushi roll in clingfilm and keep it in the fridge until it is needed.
When ready to eat, using a serrated knife, cut each roll into eight pieces.
Serve with soy sauce and wasabi, if desired, for dipping.