Carefully remove the liver from the dogfish and put it aside. After taking off the head, wash the fish carefully and cut it into pieces that you will boil in salted water. Drain the fish and put it in a pot. In the meantime, shell the walnuts, put the kernels in a mortar, add the liver, parsley and garlic.
Pound all the ingredients and then fry to a light brown in a pan with ½ cup of oil. Add 1 glass of white vinegar and boil for a few minutes. Pour the sauce, while it’s still hot, on the fish. Prepare this dish at least 12 hours before eating, so that the fish can absorb the sauce.