Yucatan leg of lamb

Ingredients

1 whole leg of lamb (approx. 6.5 pounds)
1.5 tbsp. cumin seeds
3   tbsp. black peppercorns
3   tbsp. dried orregano leaves
3   tbsp. dried thyme leaves
..5  tsp.  sea salt (I use regular salt)
3-4  dried chipotle chile (essential - these are smoked jalapeno)
3   tbsp. olive oil
8 - 10 prickly pear cactus pads (optional - these are sold as nopales)
salt and pepper to taste
6 cups reserved lamb stock (I use beef stock with equally good
results)

Instructions

Preheat oven to 325 Trim fell and fat from leg of lamb. (The fell is is what gives lamb its strong taste. It is important to remove it as thoroughly as possible). Remove hip bone with a boning knife (I usually leave this on, it just makes carving the lamb a little more difficult). Re-form the lamb and tie tightly with kitchen string. Make a stock with the bones and trimmings and set lamb aside, covered with plastic wrap. In a small iron skillet, saute the cumin seeds, peppercorns, orregano, and thyme over medium heat to release their flavours. Stir frequently and remove when they turn brown and start to smoke. Add salt and one broken chipotle chili, and grind the mixture into a fine powder in a clean coffee grinder. Rub lamb with olive oil and then coat uniformly with generous amounts of the spice mixture. Place on a rack in a shallow roasting and roast for 1 hour and 15 minutes - until a meat thermometer registers an internal temperature of 120 F. Rasie heat to 450 F to brown exterior for 5 to 10 minutes (the meat thermometer is important to judge the doneness of the meat). The internal temperature should rise to 130 F. Remove from oven and let rest for 15 min. before carving to allow the meat juices to be reabsorbed. While the lamb is roasting, wash the prickly pear cactus pads in cold water, after removing the thorns with a paring knife, brush with olive oil and sprinkle with salt and pepper. Grill over a low charcoal fire or under a broiler for about 5 min. per side or until tender. To make the sauce, pour the fat from the roasting pan and add the lamb stock (or beef stock in my case), and remaining broken chipotles. Reduce over high heat, stirring occasionally, until stock is reduced by two-thirds. Adjust seasoning. Carve lamb and serve on the platter with rice, garnish with cactus pads and spoon sauce over meat. Note: Lamb can marinate overnight in the refrigerator, covered with plastic wrap. It is important to