Place each chicken breast between 2 pieces of heavy plastic wrap. Pound with flat side of a meat mallet to about 1/4-inch thickness. Coat chicken pieces lightly with flour, shaking off excess. In a large skillet heat butter and oil over medium heat. Add chicken pieces, two at a time, and cook about 1 minute on each side, or until no longer pink. Remove to serving platter; repeat with remaining chicken pieces. Keep chicken warm. Reserve any drippings in skillet.
Add garlic, anchovy fillets, and olives to skillet; cook over medium heat for 1 minute. Add tomatoes; mash with fork. Stir in wine and ground pepper.
Bring to boiling. Reduce heat; simmer gently, uncovered, 4 to 5 minutes or until juices are slightly thickened. Stir in basil, parsley, and capers; heat through. To serve, spoon tomato mixture over chicken pieces on serving platter. Makes 4 servings.