Rub lamb all over with olive oil, rosemary and garlic then sprinkle with salt and pepper.
2.4 kg lamb shoulder (bone in), 1 tablespoon olive oil, 3 teaspoon fresh rosemary leaves, 4 garlic cloves, ½ teaspoon salt, black pepper
Place lamb in the slow cooker and pour the beef stock around the lamb (not over the top) and cook for 10 hours on low setting (refer to your slow cooker's instructions).
2 cups beef stock
Towards the end of the lamb's cooking time, preheat oven to 200c.
When it's finished, take the lamb out of the slow cooker and place it in a baking dish (be careful as you transfer it, it will be very soft) and pour the cooking juices into a jug, skim off any fat and set aside to make the gravy.
Bake lamb uncovered for 20 minutes until browned on top.