Preparation / Directions:
Make sure that all the fat has been trimmed from the outside of the leg and that most of the fell (parchment-like white skin) has been pulled off. Put the leg in a baking dish made, preferably, of Pyrex or stainless steel. Put the 2 oz. almonds, onions, garlic, ginger, green chiles, and 3 tablespoons of the yogurt into the container of a food processor or blender and blend until you have a paste. Put the remaining yogurt into a bowl. Beat lightly with a fork or a whisk until it is smooth and creamy. Add the paste from the processor, the cumin, coriander, cayenne, salt and garam masala. Mix.
Push some of the spice paste into all the openings in the lamb. Be quite generous. (I forgot to say, you need to ask the butcher to make a deep pocket to hold a "stuffing", in this case, some spice paste mixture, or make a pocket yourself) Spread the paste evenly on the underside of the leg (the side that originally had less fat.) 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. Spread a very thick layer of paste over it. Again, make deep slashes with the knife and push the spice paste into the slashes. Pour all the remaining spice paste over and around the meat. Cover with plastic cling film and refrigerate for 24 hours. Take the baking dish with the meat out of the refrigerator and let the meat come to room temperature. Remove the cling film. Heat the oil in a small frying pan over a medium flame. When hot, put in the cloves, cardamom, cinnamon and peppercorns. When the cloves swell - this takes just a few seconds - pour the hot oil and spices over the leg of lamb. (My note: I found the spices jumped and spat in the oil quite a lot - make sure your arms and counter are well protected)
Preheat the oven to 400F. Cover the baking dish tightly either with its own lid or with a large piece of aluminum foil. Bake, covered, for 1 hour 30 minutes. Remove the foil and bake uncovered for 45 minutes. Baste 3-4 times with the sauce during this period. Scatter, or arrange in a pattern, the sultanas and the 1/2 oz. almonds over the top of the leg and bake for another 5-6 minutes. Remove the baking dish from the oven and let it sit in a warm place for 15 minutes. Take the leg out of the pan and set it on a warm platter. Spoon off all the fat from the top of the sauce. Use a slotted spoon and fish out all the whole spice in the sauce. Discard the spices. Pour the sauce around the leg.