Preheat the oven to 160°C. Combine the breadcrumbs, sausage meat, parsley and seasoning in a large mixing bowl until combined. Lay the lamb shoulder on a flat surface and season the inner side of it.
Arrange the stuffing in the centre evenly and wrap up into a tight package. Tie using butcher's twine at 2inch intervals to secure well. Rub the outside of the stuffed shoulder with olive oil and season well. Sear in a hot frying pan set over a high heat until golden all over. Tuck a sprig of rosemary under the butcher's twine.
Arrange the vegetables in a large casserole dish and pour the stock in. Sit the lamb on top and roast for 2-2 ¼ hours until done. Remove and allow the lamb to rest for 10 minutes before garnishing with the remaining rosemary sprigs inside the dish and outside as well before serving.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.