- Heat a 6-quart Dutch oven over medium high heat. Add oil and heat for one more minute.
- Season shortribs with salt and freshly ground black pepper. Add to Dutch oven and cook until deeply browned on all sides. Remove and keep warm.
- Add remaining oil and onion and sauté until lightly browned at the edges. Add potatoes, shortribs, and remaining ingredients except rosemary.
- Place in a cold oven then turn oven to 250°F and bake for 5½ hours.
- Remove and skim fat. Serve sprinkled with rosemary.