1 lb (454 g) very fresh tuna or salmon, thinly sliced (as thin as smoked salmon slices)
2 teaspoons (10 ml) toasted sesame seeds
4 green onions, thinly sliced
1/4 cup (60 ml) pickled ginger
1 sheet nori, cut into 4 strips and thinly sliced
Place rice in a bowl and cover with cold water. Rinse rice gently until water becomes cloudy. Drain and repeat four to five times or until water runs completely clear. Leave rice in the colander until it is well drained.
In a medium saucepan, bring rice and water to a boil. Stir, cover and simmer for about 15 minutes or until liquid is completely absorbed. Stir and let stand for 5 minutes, covered.
Meanwhile, in a small saucepan, gently heat vinegar, mirin, sugar and salt. Pour into cooked rice and toss gently to coat.
Spread rice on a baking sheet, tossing gently to aerate it. Cover with plastic wrap and let cool.
In a bowl, combine soy sauce, mirin and wasabi. Add fish and coat well.
Place rice in four bowls and top with salmon slices, overlapping them. Sprinkle with sesame seeds, green onions, pickled ginger and nori with a little wasabi.