- Dredge veal osso buco in flour and season well with salt and pepper and set aside. Heat olive oil in a large pot over medium-high heat and brown the osso buco on both sides until golden brown, about 7 minutes on each side.
- Add onions, celery, garlic, and carrot and cook, stirring, until tender about 7 minutes. Add red wine and balsamic vinegar and reduce to a syrupy consistency, about 35 minutes.
- Add tomatoes and their juices, 2 cups water, and beef broth. Increase heat to medium and add osso buco, crushed red pepper flakes, and rosemary.
- Season with salt and pepper, partially cover and allow to simmer until meat is tender, about 2 ½ hours.