1. Heat the oil in a pan then add the butter and let it melt. Meanwhile, pass the meat through the flour. Fry the meat on both sides for 2-3 minutes.
2. Add the white wine to the meat pan and simmer for 3-4 minutes. Add the beef soup, garlic and lemon zest. Partially cover the pan and let it boil for 50 minutes, turning the meat from time to time.
3. After 50 minutes, remove the meat and wrap it again in aluminum foil. Dissolve the flour in cold water and add it to the sauce in the pan, stirring. Add the parsley, salt and pepper to taste. Let the sauce thicken slightly. .
4. Serve the meat with sauce and mashed potatoes with butter.