Heat a fry pan to very hot and add a small amount of cooking oil to pan. Carefully sear each side of the tuna brick for five seconds each.
Sprinkle all sides of the tuna with sesame seeds and set aside.
Blanch ginger and garlic in boiling water and refresh in iced water, three times. Squeeze out and place in a small bowl. Add coriander roots, both soy sauces, sesame oil, extra virgin olive oil and combine.
Cut daikon into strips, 1cm wide and 10cm long.
Boil sugar, water, salt and vinegar together to dissolve and pour over daikon. Refrigerate until needed.
Carefully cut tuna into six even sized pieces and arrange neatly on a plate. Dress generously with soy and ginger dressing. Arrange sea grapes, candied yuzu, seaweed, red shiso leaves and pickled daikon strips on top.
