Preheat barbecue to hot. Make small incisions on the surface of the shoulder. Rub the lemon juice and oregano into the Lamb. Season with salt and pepper.
Barbecue the Lamb for 15 minutes on one side and then turn it over and cook for a further 15 minutes. Cover loosely and rest for 10 minutes.
Combine remaining ingredients to make a salad. Sliced the Lamb shoulder and serve with the Greek salad.