Heat the oil in a pan. Sauté the onion and garlic. Add the tomatoes and tomato puree, cook briefly and season, simmer over a low heat for approx. 30 mins.
Season the meat. Empty the flour into a shallow dish. Beat the eggs and parmesan in a deep bowl. Toss the meat in the flour and then dip in the egg mixture. Heat the clarified butter in a non-stick frying pan. Reduce the heat, fry the meat in batches over a medium heat for approx. 1 1/2 mins. on each side. Serve the tomato sauce separately.