01 -
Cut two 10×2.5 cm blocks from the watermelon. Place in an oiled ovenproof dish, drizzle with sunflower oil, and roast at 180°C (350°F) for 20 minutes. Flip the blocks and bake for another 10 minutes. Allow to cool slightly.
02 -
Mix tamari, mirin, sesame oil, and rice vinegar in a bowl. Pour the mixture over the warm watermelon, cover the dish, and let it rest for 20 minutes. Then refrigerate the watermelon for 1 hour or overnight.
03 -
Rinse the sushi rice until the water runs clear. Combine 1¼ cups of cold water and the rice in a pan, bring to a boil, then simmer covered for approximately 15 minutes. Remove from heat and let the rice stand for 10 minutes. Separately mix rice vinegar, raw caster sugar, and salt until dissolved. Gently fold the mixture into the rice and cover with a damp cloth to cool.
04 -
Shape the prepared sushi rice into 5 cm logs. Slice the marinated watermelon at an angle to resemble tuna slices. Lay the watermelon slices over the rice pieces and top each with pickled ginger before serving.