1. Preheat oven to 450°. Follow directions for heart-shaped parchment package at lower left.
2. Unfold parchment heart, and coat lightly with cooking spray, leaving a 2-inch border ungreased at edge.
3. Place 1/2 cup arugula on one side of parchment-paper heart so that it touches fold, but not ungreased border. Place a chicken breast over arugula; sprinkle with 1/2 teaspoon sage and 1/2 teaspoon rosemary. Top with 1/4 cup tomato. Sprinkle with one-fourth of salt and black pepper, drizzle with 1 teaspoon olive oil, and top with 1 teaspoon olives, if desired.
4. Fold paper; seal edges with narrow folds. Repeat with the remaining parchment paper, chicken, and other ingredients.
5. Place packets on baking sheets. Bake at 450° for 20 minutes or until puffy and lightly browned. To serve, open packets and transfer arugula and chicken breast to plates; pour juices over top. Or serve right in packets; carefully transfer to plates and pierce each to allow steam to escape.