Clean and fillet the dog-fish. Finely chop a battuto with a handful of parsley and garlic. Peel and thinly slice the potatoes. Pour 2 oz. of oil into a baking pan and add half of the battuto. Make a layer of potato on top of the battuto and add half the Pecorino. Lay the fish fillets on top of the potatoes and cover with another layer of potatoes and cheese. Drizzle with oil, salt, pepper and bake in a hot oven for about 40 mins. Shake the pan occasionally during baking so that the potatoes do not stick to it. Serve in the baking dish it has cooked in.
