Trim excess fat before cooking. Sometimes lamb and mutton fat is covered with a thin, papery membrane called the fell. This should be trimmed off before cooking.
For best results when roasting lamb or mutton, use a meat thermometer inserted in the thickest part of the meat, making sure the thermometer is not touching a bone. Internal temperatures should reach 135 to 140F (57 to 60C).
Mutton can be tenderized by marinating in acidic ingredients (for no more than 24 hours), or pounding the meat with a mallet to break down connective tissues.
Wipe the meat with a clean, damp kitchen towel. Place fat side up on a rack above a shallow roasting pan. Insert meat thermometer deep into the meat. Roast at 350F (180C) until it reaches a temperature of 135F to 140F (57 to 60C).
Wipe the meat with a clean, damp kitchen towel. Place the steaks on a rack above a shallow roasting pan. Adjust the oven rack so meat is 3 inches (about 7.5cm) from the heat source for thin cuts, 4 inches (about 10cm) for thick cuts. Turn with a fork or tongs after four to five minutes. Cook until desired internal temperature is reached, about four to six minutes per side.
Heat a heavy skillet over medium heat until very hot. Wipe steaks with a clean, damp kitchen towel before placing them in the skillet. Sear until brown on each side. Pour off drippings and turn the meat frequently until done.
Wet-heat cooking works well for tougher cuts of meat, such as shank and shoulder. Wipe the meat with a clean, damp kitchen towel. Heat a heavy skillet or Dutch oven over medium heat until very hot. Add oil or butter, then add the meat, and brown it on all sides. When all the meat is browned, add cooking liquid and cover tightly with a lid. Cook in an oven preheated to 325F (160C), or on the stovetop over low heat, until lamb is tender, 30 to 35 minutes per pound (454g).
Wash and pat dry stew meat or shanks. Dredge in flour and spices and brown in oil if desired. Then put in a Dutch oven and cover with liquid and herbs, spices, and vegetables. Cook in the over at 325F (160C) or on the stovetop over low heat until lamb is tender.
Place lamb or mutton roasts, fat side down, on a roasting rack over a microwavable dish. Cook on High 10 to 12 minutes per pound (450g). Turn halfway through. Let stand 10 to 15 minutes. Arrange chops in a single layer in a shallow baking dish. Cook on high 7 to 10 minutes per pound (454 grams). Rotate dish half-way through cooking time.
Place steaks, chops, or ribs on a prepared grill with the rack about 8 inches (about 20cm) from the heat source. Grill about four minutes per side. Homemade or bottled barbecue sauce (or other glaze) may be brushed on lamb or mutton before and during grilling.
To test the temperature, place your palms above the coals or heat source at cooking level. If you have to remove your hands after two seconds, the temperature is hot; after three seconds, medium hot; and after four seconds, medium. More than four seconds indicates the grill has not reached cooking temperature.