Rinse and Cook the Rice: Place the rice in a bowl and cover with cold water. Swirl the rice with your hand, then drain. Repeat this process 4-5 times until the water runs almost clear. Drain the rice thoroughly and place it in a medium saucepan with the 350ml of cold water. Bring to a boil, then immediately reduce the heat to the lowest setting, cover with a tight-fitting lid, and simmer for 15 minutes. Do not lift the lid. After 15 minutes, remove from the heat and let it stand, still covered, for another 10 minutes.

Prepare the Seasoning: While the rice is cooking, gently heat the rice vinegar, sugar, and salt in a small pan over low heat. Stir until the sugar and salt have completely dissolved. Do not let it boil. Set this aside to cool slightly.

Season the Rice: Transfer the hot cooked rice to a large, non-metallic bowl (a wooden or glass one is ideal). Pour the vinegar mixture evenly over the rice. Using a rice paddle or wooden spoon, gently 'cut' and fold the seasoning through the rice. I find that fanning the rice with a magazine or piece of card as you do this helps it cool down faster and gives it a lovely gloss. Let the rice cool to room temperature, which can take about 30 minutes.

Prepare the Fillings: While the rice cools, prepare your fillings. Slice the sushi-grade salmon into long strips about 1cm thick. Peel the avocado, remove the stone, and slice it into thin strips. Cut the cucumber into long, thin batons (julienne).

Assemble the Roll: Place your bamboo mat on a clean work surface. Lay one sheet of nori on top, shiny-side down. Have a small bowl of water nearby (Tezu). Dip your fingers in the water to prevent the rice from sticking to them. Take a handful of rice (about 1/4 of the total) and spread it evenly over the nori, leaving a 2cm border at the top edge. Be gentle and don't press down too hard.

Add the Fillings: Arrange a line of your fillings (a few strips of salmon, avocado, and cucumber) horizontally across the centre of the rice. What works best for me is not to overfill the roll, as this makes it very difficult to close. Less is more!

Roll the Sushi: Using the edge of the bamboo mat closest to you, lift it and start to roll it over the fillings, tucking the edge of the nori into the roll to secure them. Keep a firm, even pressure as you continue to roll away from you until the entire roll is formed. Squeeze the mat gently around the roll to compact it and ensure it's a tight cylinder.

Slice and Serve: Use a very sharp, slightly wet knife to slice the roll. First, trim the uneven ends, then slice the log into 6-8 equal pieces. Wipe the knife with a damp cloth between each cut for the cleanest slices. Serve immediately with soy sauce, wasabi, and pickled ginger.