1 Kg sardines, 1 kg white onions, 1 cup red wine vinegar, vegetable oil, flour, salt and pepper
Clean the sardines: remove the heads and the fish-bones. Then open the filets flat, like books. Coat the sardines with flour, fry them and set them aside. Finely slice the onions. Slowly stew the onions in a closed saucepan with 4 spoons of oil. When they are almost ready, raise the flame and let them brown just a bit. Then add the vinegar, salt and pepper and let boil for few minutes. At the end, in another pan, alternate layers of onions and layers of sardines, ending with the onions. If necessary dress with oil mixed with little vinegar. In winter, Venetians used to add raisins and pine nuts to the onions, in order to make the sauce richer and tastier.