Instructions

1. In a large wide and heavy-bottomed pot, melt the butter. Add the onion, celery and carrots, and cook over moderate heat, covered, for 5 minutes, until the vegetables are softened slightly. Uncover and cook an additional 3 minutes, until the vegetables are slightly browned.
2. Stir in the tomato paste, then add the flour and cook for 1 minute, stirring. Add the wine and stock and bring to a simmer.
3. As the vegetables are cooking, heat the olive oil in a large skillet until shimmering. Season the ribs with salt and pepper on all sides, then add them to the pan and cook over high heat, turning, until each side is browned, about 15 minutes. (Brown the ribs in batches if your skillet, like mine, isn’t large enough for all 6 at once.)
4. Transfer the short ribs to the pot. Cover and cook over medium low heat until the ribs are very tender, about 2 hours.
5. Transfer the ribs to a plate and remove the bones. Skim off fat from the top of the casserole. Boil until reduced to 2 cups, about 10 minutes. Return the meat to the sauce and simmer over low heat until heated through.