Season veal generously with salt and freshly ground black pepper. Heat butter and olive oil in a large heatproof casserole, and brown veal on all sides in fat to seal in juices. Remove veal.
Chop onions, carrots, celery and garlic, and brown them in the pan, stirring constantly. Sprinkle with flour and stir until flour is absorbed by the mirepoix of vegetables. Return veal to the