Preheat oven to 425°.
Place potatoes, tomatoes, and carrots on a jelly-roll pan coated with cooking spray. Drizzle vegetable mixture with olive oil; sprinkle with 1 tablespoon chopped rosemary, 1 teaspoon thyme, 3/4 teaspoon salt, and 1/4 teaspoon pepper. Toss gently, and spread into a single layer on pan. Bake at 425° for 30 minutes. Remove vegetable mixture from pan, and keep warm.
Sprinkle chicken with remaining 1 1/2 teaspoons chopped rosemary, remaining 1 teaspoon thyme, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon pepper. Add chicken and olives to pan. Bake at 425° for 35 minutes or until chicken is done. Garnish with rosemary sprigs, if desired.