Preparation Whisk first 5 ingredients in large glass baking dish to blend. Add lamb; turn to coat. Cover and refrigerate overnight. Prepare barbecue (medium-low heat). Grill lamb to desired doneness, turning chops occasionally, about 25 minutes for medium-rare. Meanwhile, boil chicken stock and next 4 ingredients in small saucepan until reduced to 3/4 cup, about 12 minutes. Reduce heat to low. Add green onions and butter, stirring until butter melts. Cut lamb between ribs into chops. Place chops on plates; spoon sauce over.
Preparation Whisk first 5 ingredients in large glass baking dish to blend. Add lamb; turn to coat. Cover and refrigerate overnight. Prepare barbecue (medium-low heat). Grill lamb to desired doneness, turning chops occasionally, about 25 minutes for medium-rare. Meanwhile, boil chicken stock and next 4 ingredients in small saucepan until reduced to 3/4 cup, about 12 minutes. Reduce heat to low. Add green onions and butter, stirring until butter melts. Cut lamb between ribs into chops. Place chops on plates; spoon sauce over.