Put a large skillet on medium-high heat and spray with cooking spray. Cook chicken breast on each side for about 6-8 minutes (depending on thickness) or until done (160 F). Remove chicken from pan and cover to keep warm.
Add lemon zest, garlic and rosemary to the still heated pan and sauté for about 30 seconds.
Add tomatoes and olives and cook, scraping up any browned bites, until tomatoes are hot, about 4 minutes.
Stir in olive oil and salt & pepper to taste. Put on top of chicken breast and serve.