Heat the oven to 300°F.Season the short rib all sides with salt and freshly ground pepper. Heat the oil over medium-high heat in a medium oven proof pot. Sear all sides of the beef, until well browned. Remove and set aside.Add the pancetta and cook, stirring, until crispy and brown. Add the chopped onions and garlic and cook, over medium until golden. Stir in the flour and cook, 1-2 minutes. Add the wine and bring to a boil, scraping and deglazing the pan. Add the beef broth, tomato paste, bay leaves, thyme, and short rib. Bring to a simmer, then cover.Braise in the oven, covered for 2-3 hours, or until the meat is tender. Where there’s 45 minutes left on the cooking time, stir in the the vegetables, cover and continue to cook. When done, taste and season with salt and pepper. Finish with parsley and enjoy with pasta or bread.