Combine first 4 ingredients. Sprinkle lamb with salt; rub with 1 tablespoon oil mixture. Place on a broiler pan coated with cooking spray. Broil 4 minutes on each side or until done.
While lamb cooks, heat a medium saucepan over medium-high heat. Add remaining oil mixture; cook 20 seconds, stirring constantly. Stir in broth; bring to a boil. Stir in couscous. Remove from heat; cover and let stand 5 minutes. Fluff with a fork. Stir in tomatoes, olives, and cheese. Serve couscous mixture with lamb.