Preheat the oven to 375 degrees F.
With the point of a knife make small slits, about 1-inch deep, in the fat side of the roast. In each slit stuff 1/2 clove of garlic. Rub the rosemary, salt and pepper over the roast. Place the roast over a bed of mirepoix or in a roasting rack. Cook for 30 minutes. Lower the heat to 250 degrees F. Continue cooking until internal temperature reaches 150 degrees F, about another 1 1/2 to 2 hours. Remove from heat and let rest for 15 minutes before slicing.
Serve as an open faced sandwich with 2 to 3 slices of Roast Leg of Lamb with Dijon mustard.
The night before, combine the sour dough starter, 2 1/2 cups flour, and warm water in a large, non-metallic bowl. Use a large enough bowl to allow batter to ferment and rise. This mixture will be thick and lumpy but will thin down during the night. Cover and let stand in a warm place. The next morning remove and refrigerate 1 cup of this batter as a starter for the next batch. Add eggs, oil, sugar, baking soda, and salt. Let this dough sit at least 3 hours. Roll the dough out on a well-floured surface to about 1/2-inch thick. Cut into 4 to 5-inch squares. Carefully deep -ry the scones until golden brown on both sides.
Mix together milk and flour and let stand 48 hours or until it starts to ferment. Hold starter in a pottery or glass container in the refrigerator. Never use a metal container or leave a metal spoon in the starter. If starter will not be used once a week, freeze the starter to keep it from getting too active.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.