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 5 cm 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 50ºC 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