Combine the wine,oil,mustard,vinegar,rosemary leaves,peppercorns, oregano,and garlic in blender. Puree for 3 minutes or until rosemary is completely ground. Place lamb in large glass baking dish with 2-inch high sides. Pour marinade over lamb, cover completely and evenly.Cover; chill at least 8 hours or overnight. Let stand 2 hours at room temperature before cooking.
Prepare barbecue (medium-high heat). Remove lamb from marinade. Sprinkle generously with salt and pepper. Grill turning occasionally,lamb until brown and crusty on outside and thermometer inserted into thickest part registers 130 F for medium-rare., Transfer to platter and tent with foil. Let stand 10 minutes. Cut on diagonal into thin slices.
6 Servings Bon Appitit June 1996