Place lamb in a deep glass or enamel pan. Combine reamining ingredients and pour over meat; let stand in refirgerator for 24 hours, turning meat occasionally.
Drain meat; place on rack in an open roasting pan. Roast in a very hot oven 450° F for 15 minutes. Reduce oven temperature to moderate 350° F, pour marinade over meat and continue roasting meat for about 2-1/2 hours or until done to your liking; 140° for rare, 160° for medium.
Baste frequently during roasting. If pan juices cook down too quickly, add a few tablespoons of boiling water to prevent burning.
At serving time, skim fat off pan juices. Serve juices with meat if desired.
Servings: 8 to 10