Drizzle the lamb with 1tbsp of the oil and season. Cook in a hot pan until browned all over.
Mix together the harissa, remaining oil and lemon juice.
Spread the harissa mix all over the lamb and roast for 3 hours at 160°C/325°F/Gas 3.
Cook the USA Wild rice-long grain rice mix together for 20-25 minutes.
Mix together the onion, chilli and and lime juice.
Add the cooked rice to the onion and chilli and then add the mango. Mix well.
When the lamb is cooked, remove from the oven and allow to rest for 10 minutes. Shred with a sharp knife.
Serve the lamb and rice salad topped with the chopped herbs and the Greek yogurt on the side.
A leg of lamb is really forgiving when it comes to cooking time. Every oven will vary, so if you find the meat isn't quite tender enough, the you can put it back in the oven and it will still be nice and juicy even if it is cooked for 45 minutes to an hour longer.
The nutritional information for this will not be totally accurate, because there is a lot of fat the comes out when cooking, which is not used.
You don't even need to carve this lamb. It should be so tender that you should be able to pull the meat off the bone with two forks.