Steam the rice and let it cool slightly.
Mix one tablespoon of soy, two teaspoons of mirin, one teaspoon of sake and a dash of extra virgin olive oil Reserva Familiar Picual Castillo de Canena.
Marinate the tuna in the mixture for 3 - 5 minutes.
In a bowl, place the rice and on top, the tuna.
Sprinkle the chopped spring onion, crushed nori seaweed and sesame seeds. If you have them, you can put shiso leaves to taste, cut into julienne strips on top (optional).
Finish with a few drops of AOVE Reserva Familiar Picual and serve.