Combine first 5 ingredients in a zip-top freezer bag; add lamb. Seal and chill at least 8 hours.
Soak skewers in water to cover 30 minutes. Brush herbs and garlic off lamb, and discard marinade. Thread lamb onto skewers, and sprinkle with salt.
Grill over medium heat (300° to 350°) for 4 to 5 minutes on each side or until desired degree of doneness. Let stand 5 minutes. Serve with Tapenade.