Slow Roasted Shoulder of Lamb with Merguez spices

I don't ofter blip food but last week I spotted a recipe in one of my cookbooks that I really fancied trying having never cooked a shoulder of lamb ... slow roasted shoulder of lamb with merguez spices. Our butcher calls on a Saturday morning and he gave me a slightly strange look when I asked whether it was possible to have half a shoulder so I ended up with the whole thing. The spices were gently toasted and ground before being turned into a paste to cover the joint. It will have been slow roasting for over six hours. There is probably enough for eight and seeing as Mr.B is currently on a train being curtailed at Preston I may have to come up with some creative ways of using up the large amount of left-overs.