1. Prepare grill.
2. Combine yogurt and next 3 ingredients. Stir in 1/8 teaspoon salt and 1/8 teaspoon pepper. Chill.
3. Sprinkle lamb evenly with remaining 3/8 teaspoon each salt and pepper. Place lamb on grill rack coated with cooking spray; grill 3 minutes on each side or until desired degree of doneness. Serve with yogurt sauce.
Serve with: Couscous Salad