First, turn the oven on to 200ºC/400ºC/gas 6 to pre-heat
Next, take the cinnamon, coriander, cumin and dry, hot fry until you can smell them (approx 30 seconds) then grind to a powder and add the turmeric
In a bowl, mix the yoghurt and garlic (season to taste) and half the spice mix
Put the lamb on a roasting tray and rub a tablespoon of oil and season with salt and pepper. Then cover the lamb with your spice-yoghurt mixNote: if you have time, place in the fridge for at least a few hours to marinade it. if you're super organised, do it the day before and leave overnight
When the oven is ready, pop in and leave top cook for 1 hour 15 minutes (pink) and remember to rest for 15 - 20 minutes. (I use a meat thermometer to check it's on track and I haven't blown it!)
Serve with the rest of the spice-yoghurt mix
TIPThis recipe was inspired by Thomasina Miers who does a fantastic slow-cooked lamb shoulder. Try it, it's fab. I adapted it for the leg of lamb but she instructs you to:Heat the oven to 190C (170C fan)/375F/gas 5, roast the lamb for 20 minutes, turn down the oven to 160C (140C fan)/325F/gas 3 and roast for a further three to four hours, until the meat is falling apart and soft.