Bring broth to a boil in a medium saucepan; gradually stir in couscous. Remove from heat; cover and let stand 5 minutes or until done. Fluff with a fork.
While couscous stands, spread 2 tablespoons pesto over both sides of lamb. Spread 1 1/2 teaspoons pesto over cut sides of tomatoes. Place lamb and tomatoes on a broiler pan coated with cooking spray. Broil 5 minutes; turn lamb chops, and broil an additional 5 minutes or until desired degree of doneness. Serve with couscous.