Heat the smoker to 125 degrees C. Add a chunk or two of hickory to create a steady stream of smoke.
Place the lamb shoulder on the smoker and smoke for 3 hours.
Wrap the shoulder in the foil with the brown sugar and beer. Return to the smoker and cook for a further 3 hours. When cooked the meat will be pulling back exposing the bone and separate if rubbed between your fingers.
When cooked let rest in the foil for 30 to 60 minutes.
To Serve: Pull the lamb apart gently with two forks to create small strips of meat. Stir the mint sauce through then serve immediately while still hot. If the lamb looks a little dry add some of the liquid from the foil to moisten.
The smoking time may vary based on the size of the lamb shoulder, this is based on the standard supermarket sized lamb shoulders available.