Finely chop the onion, carrot and celery.
Heat the oil in a heavy-based saucepan. Add the chopped vegetables and fry for 5 minutes or until soft.
Add the meat, season with salt and pepper. Cook, stirring well, until the veal changed colour.
Add the tomato purée, toss for 1-2 minutes.
Pour in the wine,turn up the heat and boil for 2-3 minutes. When the wine is almost completely absorbed, add some stock (and milk if used) - just enough to cover the meat. Add the bay leaves.
Bring to the boil and then simmer on a low heat for 1-2 hours.
Check on it from time to time - if it's too dry, top up with stock.
Add the vinegar five minutes before you turn off the heat.
Serve with freshly cooked pasta, sprinkled with grated Parmesan cheese.