Soak the ox-tail in boiling water for 5 minutes. Then brush and clean it. Cut the ox-tail into sections according to its cartilage. Put them in a pan. Add 1 cup of tomatoes, 6 cups of water (enough to cover the ox-tail) and 1 tablespoon of wine. Cover. Stew about 3 hours over low heat until tender.
Heat 3 tablespoons of oil in a frying pan. Fry the onion cubes