1) Make sure that all the fat has been trimmed from the outside of the lamb leg and that most of the (parchment-like white skin) has been pulled off.

2) Put the lamb leg in a baking dish made, preferably, of pyrex or stainless steel. Add the almonds, onions, garlic, ginger, green chillies, and 3 tablespoons of the plain yogurt into the container of a food processor or blender and blend until you have a paste. Put the remaining yogurt into a bowl.

3) Beat lightly with a fork or a whisk until it is smooth and creamy.

4) Add the paste from the processor, the cumin, coriander, cayenne, salt and garam masala and mix. Push some of the spice paste into all of the openings in the lamb.

5) Spread the paste evenly on the underside of the leg (the side that originally had less fat.)

6) Now, using a small, sharp, pointed knife make deep slashes in the meat, and push in the spice paste with your fingers. Turn the leg over so its outer side (the side that was once covered with fat) is on the top.

7) Spread a very thick layer of paste over it. Again, make deep slashes with the knife and push the spice paste into the slashes.

8) Pour all of the remaining spice paste over and around the meat. Cover with a plastic cling film and refrigerate for 24 hours.

9) Take the baking dish with the meat out of the refrigerator and let the meat come to room temperature. Remove the cling film.

10) Heat the oil in a small frying pan over medium flame. When it gets hot, put in the cloves, cardamom pods, cinnamon and peppercorns. When the cloves swell - (this takes just a few seconds) - pour the hot oil and spices over the leg of lamb.

11) Preheat oven to gas mark 6, 400 F. Cover the baking dish tightly either with its own lid or with a large piece of aluminium foil. Bake, covered, for 1 hour and 30 minutes.

12) Remove the foil and bake uncovered for 45 more minutes.

13) Baste 3-4 times with the sauce during this period. Scatter, or arrange in a pattern, the sultanas and almonds over the top of the leg and bake for another 5-6 minutes.

14) Remove the baking dish from the oven and let it sit in a warm place for 15 minutes.

15) Take the leg out of the pan and set it on a warm platter. Spoon off all of the fat from the top of the sauce. Use a slotted spoon and fish out all of the whole spice in the sauce. Discard the spices.

16) Pour the sauce around the lamb leg.