1. Combine first 3 ingredients in a medium saucepan; bring to a boil. Add couscous to pan. Remove from heat; cover and let stand 5 minutes. Fluff with a fork.
2. Combine hoisin and next 4 ingredients (through five-spice powder) in a small bowl. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Sprinkle pepper and salt over lamb. Add lamb to pan; cook 5 minutes on each side or until desired degree of doneness. Add hoisin mixture to pan; cook 1 minute or until thoroughly heated, turning to coat lamb. Spoon sauce over lamb; serve with couscous.