This recipe is from Bon Appétit and www.epicurious.com.
¾ cup dry red wine
½ cup extra-virgin olive oil
1/3 cup coarse-grained mustard
¼ cup red wine vinegar
4 tablespoons fresh rosemary leaves (6 sprigs)
2 tablespoons drained green peppercorns in brine
1 tablespoon dried oregano
2 large garlic cloves
1 4-to 5-pound leg of lamb, boned, butterflied, trimmed of excess fat
Combine first eight ingredients in blender. Purée until rosemary is completely ground, about three minutes.
Place lamb in large glass baking dish with 2-inch high sides. Pour marinade over lamb, making certain all parts of lamb are covered with marinade. Cover; chill at least eight hours or overnight. Let stand two hours at room temperature before cooking.
Prepare barbecue (medium-high heat). Remove lamb from marinade. Sprinkle both sides of lamb generously with salt and pepper. Grill lamb until brown and crusty on outside and thermometer inserted into thickest part registers 130 degrees for medium-rare, turning occasionally, about 20 minutes. Transfer to platter and tent with foil. Let stand 10 minutes. Cut on diagonal into thin slices.