In a saucepan large enough to hold all the cutlets in a single layer, melt the butter over medium heat and add the oil. Dry the cutlets and dredge them in a mixture of flour, salt and pepper. Shake off the excess.
Add the veal to the hot pan and brown for about 3 minutes on each side. Set them aside on a plate and add the onion, carrot, celery, pancetta, sage and rosemary in the same pan for 5 minutes. Stir in the wine and stock.
Return the cutlets to the pan with any of the juices that accumulated on the plate. Bring to the boil and then reduce the heat to low, cover and cook for about 1 hour until the veal is very tender when pierced with a fork. Turn the veal occasionally and add a little water if the sauce gets too thick. Serve hot.