Wash the rice and cook according to instructions. Brown rice will normally take a lot longer than normal sushi rice (around 40 minutes). When the rice is cooked add the rice vinegar and mirin using a gentle, cutting movement.

Brush the mushrooms with oil and fry in a pan or grill until they are almost cooked.

You can buy ponzu dressing or make a quick version by mixing 2 parts soy sauce to 1 part citrus (lemon, lime or yuzu) and a splash of mirin.

Reduce the heat and add the ponzu to the pan. Gently move the mushrooms, they will absorb the dressing and become sticky. Serve with the rice, a sprinkle with furikake and a wedge of fresh citrus fruit.