I love to cook a whole leg of lamb on the BBQ, it really works well. I prefer to use a de-boned leg of lamb, but one with the bone in would work just as well.
First of all the marinade:
200ml white wine
Juice of one lemon
100ml mirin or sherry
30ml olive oil
1 tbsp chopped fresh rosemary
1 tbsp chopped garlic
Using a small knife stab a number of holes in the leg and into these incisions stuff more garlic and rosemary. Make sure they are stuffed into the hole and not sticking out otherwise they will burn.
In a freezer bag combine all of the ingredients listed above and add the lamb leg, squeeze air out, seal bag and marinade for as long as possible, preferably overnight.
When it comes to cooking this it needs about an hour. First of all take the lamb out of the marinade and wrap it tightly in aluminium foil. Place the wrapped lamb on the BBQ (not over direct heat, you will need to move some coals to one side), close lid of BBQ and leave for 40 mins. After 40mins remove foil and cook over heat as you would normally, keep turning it around to make sure it is well cooked. The sugars in the mirin / sherry should caramelise and make the skin lovely and crispy. It will take another 20 mins or so to cook properly and you will need to keep a close eye on it to make sure that it doesn’t burn. Once cooked cut into slices or chunks and serve. I normally get a large flat platter, throw some rocquet leaves on it and place the lamb on top. This is also really lovely with a good dollop of salsa verde spooned on top.