For the sauce, heat the oil in a large heavy pan and add the whole onion, celery stick, carrot and garlic clove, with the beef bones if using.
When the bones and vegetables are nicely browned, add the tomato purée, canned tomatoes and passata.
Fill the tomato cans with water and add that to the pan with the salt and herbs.
Bring to the boil and cover the pan with a heavy lid. Reduce the heat and simmer the sauce very gently for at least two hours, preferably 4-5 hours. Stir the sauce occasionally while it cooks and as it reduces, top it up from a kettle of boiling water and allow it to reduce again. When the fat on the top of the sauce looks dark, you know it is ready.
After the final reduction, remove the bones, vegetables, bouquet garni and bay leaves. Add the Marsala, balsamic vinegar and basil leaves, check the seasoning and add salt and freshly ground black pepper if needed.
Towards the end of the cooking time, start making the meatballs. Soak the raisins in warm water for 5–10 minutes to plump them up, then drain.
Soak the sourdough bread in warm water for 2–3 minutes. Squeeze out as much water as you can then set aside.
Chop all the herbs together and mix with the garlic and toasted pine nuts.
Beat the eggs in a large mixing bowl and add salt and freshly ground pepper and a good splash of Worcestershire sauce, if using. Add the garlic, herbs, pine nuts and grated pecorino and mix well.
Break the soaked bread into small pieces and add this with the raisins to the egg mixture. With very clean hands, mix in the meats and work until smooth. Shape the mixture into balls and set these aside on a plate ready for frying.
Pour the oil into a heavy frying pan to a depth of about 5mm/¼in. Fry the meatballs in batches until brown, turning them several times to make sure they are evenly cooked.
As each batch is cooked, add the meatballs to the simmering tomato sauce. When the final batch of meatballs has been added, cook for another 30-35 minutes.
To serve, pour the sauce over cooked pasta and place the meatballs to one side.