Over high heat, add rice, salt, and 2 12 cups (625 ml) water to a large saucepan. Bringing to a boil Low-heat setting. Cook under cover for 20 minutes, or until water is absorbed and rice is soft. For 10 minutes, place covered and allow to steam.

In a bowl, combine 1/4 cup (60ml) vinegar and mirin. In a glass or ceramic bowl, put the rice. Break up any lumps with a wooden spoon or rubber spatula as you add the mirin mixture gradually and gently fold to blend. Fold the rice again after 15 minutes, or until it has cooled.

A 20 cm (base measurement) square cake pan should be greased. Allowing for the sides to overhang, and line with plastic wrap. Place cucumbers over half of the base, slightly overlapping. Place the salmon over the other side of the base, slightly overlapping it. Place the rice on top. Rice should be smoothed out in the pan using damp hands. Wrap with plastic to protect. Lastly, place a smaller square cake pan on top. On top, place the cans. Place in refrigerator to set for two hours or overnight.

Remove the top pan and cans from the rice mixture. Uncover. Onto a spotless work surface, invert. Cut the cucumber and salmon in half using a large, sharp knife. Split each half in half. A serving dish should be used. With dressing, serve.