Balsamic-Glazed Short Ribs

1 tablespoon olive oil4-5 pounds bone-in beef short ribs, well trimmedSalt and freshly ground pepper2 large garlic cloves, finely chopped#189; cup dry red wine#8531; cup balsamic vinegar 1 3-inch fresh rosemary sprigHeat the oil in a large, heavy skillet set over medium-high heat. Pat the meat dry, and add only as many pieces as will fit in the skillet without crowding. Cook until nicely browned on all sides. Transfer the meat to a large slow cooker, and brown the remaining meat. Sprinkle the ribs with salt and pepper.Discard all but 1 tablespoon of the fat, and reduce the heat to medium. Add the garlic, and cook for one minute. Add the wine and vinegar, and bring to a simmer, scraping the bottom of the pan. Pour the liquid over the ribs, and add the rosemary.Cover and cook on low for 8 hours, or until the ribs are very tender. Remove the ribs from the slow cooker, and discard the rosemary and any loose bones. Cover the ribs, and keep warm.Skim the fat off the liquid. Pour the remaining sauce into a saucepan, and cook over medium-high heat until reduced and slightly thickened. Spoon the sauce over the ribs, and serve hot.Serves six."The Italian Slow Cooker" by Michele Scicolone (2010 Houghton Mifflin Harcourt)