Instructions

1. Using a dry, heavy-based frying pan, toast the cumin seeds, peppercorns, coriander seeds, fennel seeds, fenugreek seeds, cloves, cinnamon stick and cardamom pods over a low heat. Move them around the pan on a medium heat for a few minutes, until they become very fragrant. Remove from the heat and grind to a powder in a spice grinder, then mix in the paprika and salt.
2. Combine the spice mix with the oil and garlic. Score the leg of lamb a few times on top to allow the marinade to penetrate, then smear the marinade all over the lamb, making sure to push it right into the slashes you’ve made, covering every nook and cranny.
3. Leave to marinate for at least four hours, or overnight.
4. Bring the meat out of the fridge an hour before you want to cook it, then preheat the oven to 200C/Gas Mark 6.
5. Lay the sliced onions in a roasting dish and place the lamb on top. Cook for 1 hour, uncovered, until the lamb has browned.
6. After this time, reduce the heat to 160C/Gas Mark 3. Add the lemon zest strips and water to a depth of 1cm in the base of the pan. Cover with foil and cook for 4.5 -5 hours, until the lamb is very tender. Baste the lamb with the water in the pan every hour, topping up as necessary to make sure it doesn’t dry out. Don’t skip the basting as it will keep the lamb tender.
7. Allow the lamb to rest for 15 minutes before carving.