200°C/180°C 145 °F (medium rare), 160 °F (medium), or 170 °F (well done)
“For safety, the USDA recommends cooking lamb patties and ground lamb mixtures such as meat loaf to a safe minimum internal temperature of 160 °F as measured on a food thermometer. However, whole muscle meats such as roasts, steaks, and chops may be cooked to 145 °F (medium rare), 160 °F (medium), or 170 °F (well done).  4 Roast at 425°F for 20 minutes. Then reduce the heat to 300°F and roast an additional 40 minutes (for a 6 pound boneless roast) to an hour (for a 6 pound bone-in roast). If you are cooking a roast bone-in, the bone will act as an insulator and will require a longer cooking time than a boneless roast. I’ve seen references that range from 120° to 145°F. For this roast, I pulled it out at 125°F. As it rested the internal temperature continued to rise a few points as the meat continued to cook. We like lamb on the rare side of medium rare, and this roast was perfectly done to our taste. Roast for 1 hour (this will give you a medium-rare cooked leg of lamb; roast lamb a further 30 minutes for well done). Carefully transfer the lamb to a carving plate or shallow tray, cover loosely with foil and set aside to rest. Increase oven temperature to 230°C or 210°C fan-force. Preheat oven to 220°C or 200°C fan-force. Use a small sharp knife to make 16 1cm-deep slits in the lamb. Use your fingers to press a slice of garlic and a sprig of rosemary into each slit. Place the lamb in a large ovenproof and flameproof roasting pan, and brush all over with oil. 1 For a lean piece of meat, cook at 450 degrees F (230 degrees C) for the first 15 minutes, then turn the temperature down to 350 degrees F (175 degrees C) to continue roasting–the meat will take about 25 minutes per pound to reach medium rare. A piece of meat at room temperature will roast more evenly. Use a roasting rack to ensure even browning and heat circulation around the meat. The amount of fat that your lamb has on the outside and marbled through the middle will determine the cooking time and temperature: Reduce oven temperature to 180°C/160°C fan-forced. Roast lamb, basting with remaining oil mixture every 20 minutes, for 1 hour 15 minutes for medium or until cooked to your liking. Add potatoes to pan for last 40 minutes, turning halfway through cooking. 1  Step 3. Preheat oven to 200°C/180°C fan-forced. Lightly grease roasting pan. Place lamb in pan. Combine oil, rosemary and garlic in a bowl. Rub half the oil mixture over lamb. Season with salt and pepper. Roast for 15 minutes. Preheat the oven to 400 degrees F. Using your hands, rub the lamb all over with the lemon juice. Pat the garlic and rosemary evenly all over the surface of the meat. Season the meat with the salt and pepper and place the lamb in a roasting pan. Place the lamb in the oven and roast for 30 minutes. Preheat the oven ... sheet pan and roast until it is ... top of the lamb (see tip). Meanwhile, ... stand at room temperature for 30 minutes ... before roasting. Serves 6-8. Make the mint ... aside at room temperature for 2 or ... cut slits in lamb and fill slits ... in roasting tin. Roast for 15 minutes. Roasted to Perfection. Before roasting your lamb, remove it from the refrigerator and allow it to sit for 30 minutes. A piece of meat at room temperature will roast more evenly. Use a roasting rack to ensure even browning and heat circulation around the meat. The amount of fat that your lamb has on the outside and marbled through the middle will determine the cooking time and temperature: Sear the lamb roast for 15 minutes at the higher oven temperature (450 degrees F.), then turn the oven to the lower temperature (325 degrees F.) for the rest of the cooking time. Do Not Cover the roast. Insert meat thermometer so tip is in thickest part of lamb (not resting in fat). Cook until the lamb roast reaches an internal temperature of 120 degrees F. Remove from oven, cover with aluminum foil, and let sit approximately 15 to 20 minutes. Remember, the lamb roast will continue to cook as it sets
http://startcooking.com/safe-cooking-temperatures-lamb http://www.simplyrecipes.com/recipes/roast_leg_of_lamb/ http://www.taste.com.au/recipes/12496/rosemary+garlic+roast+lamb http://dish.allrecipes.com/how-to-roast-lamb/ http://www.taste.com.au/recipes/23077/traditional+roast+lamb http://www.foodnetwork.com/recipes/emeril-lagasse/rosemary-and-garlic-roast-leg-of-lamb-recipe.html http://www.cooks.com/rec/search/0,1-0,lamb_roast_temperature,FF.html http://dish.allrecipes.com/how-to-roast-lamb/ http://whatscookingamerica.net/Lamb/Roast_Boneless-LegLamb.htm
what temperature to cook roast lamb