Spray a baking pan with non-stick spray. Make a paste of the garlic, olive oil, flour and ROAST LAMB SPICE. Cut several slits in the roast and press half of the paste into the slits. Rub remaining paste over the entire roast. Place in baking pan, cover and refrigerate 2 to 3 hours or overnight. To bake, preheat oven to 450 degrees and bake uncovered for 20 minutes. Turn down temper- ature to 275 degrees and continue baking for 2 hours (30 minutes per lb). For accuracy, insert a meat thermometer in roast before roasting. Bake until desired stage is reached. Roast will continue to cook for a few minutes after removal from oven, so underbake slightly. Remove roast from pan and cover to keep warm while preparing gravy. Slice and serve with pan gravy.   Pan Gravy: Deglaze roasting pan by adding 1 1/2 cups water to the pan and scraping loose the drippings. Pour pan juices into bowl and skim off the fat. Place 1/4 cup flour in a small saucepan and gradually stir in pan juices, whisking continuously to keep smooth. Bring to a boil, reduce heat and simmer until thickened