Since I nailed this method, it has never failed me. It is my go to when I need to cook for group lunches or dinners because it is low maintenance and I can completely trust the process. You can season the lamb with whatever you want before you put it in the oven, the recipe below keeps it simple and still delicious. If it is a smaller piece of lamb just keep your eye on it at about 3 hours, if its feeling soft then pull it out then, take the foil off and turn up the oven.
1 lamb shoulder (approx. 2 kgs, bone in)
Salt & Pepper
Heat the oven to 150ºC
Drizzle olive oil into a baking tray
Place lamb into tray, drizzle with olive oil and season with salt & pepper
Cover tightly with foil
Place into oven
Leave in oven for 4 and 1/2 hours
Take the lamb out of the oven, turn the oven up to 200ºC, take the foil off the lamb and put it back into the oven for 30 minutes more
Remove from oven, cover with foil again and rest for 10 minutes
Shred with tongs or forks..