Preheat the oven to 110C/90C Fan/Gas ¼.
Remove the roes and blend three with 1 tablespoon of the butter in a food processor until smooth. Place in the fridge.
Dry the remaining three roes in the oven for 5 hours. Blend into a fine powder and store in a screw-top jar until needed.
Heat 1 tablespoon of the butter in a large saucepan and gently fry the shallot for 5 minutes, or until soft and translucent. Add the rice to the pan and stir until the grains are coated in butter.
Pour in the wine and cook until evaporated. Add the hot stock a ladleful at a time, stirring constantly, until the liquid has evaporated. Continue until the stock is used up and the rice is al dente (this will take about 20 minutes).
Stir in the roe butter and Parmesan and cook for 2 further minutes. Place a lid on and set aside.
Fry the scallops in the remaining butter for 2–3 minutes on each side, or until just cooked through.
Meanwhile, blanch the cabbage in boiling salted water for 2 minutes and refresh in iced water, then drain well. Cut out six circles and fry in the oil until crisp.
Serve the risotto garnished with the crispy cabbage and scallops and eat immediately.