1. Heat a grill pan over medium-high heat. Add 1 teaspoon oil; swirl to coat. Sprinkle chicken with salt and pepper. Add chicken to pan; cook 6 minutes on each side or until done.
2. While chicken cooks, combine remaining 1 teaspoon olive oil, basil, and vinegar in a medium bowl, stirring with a whisk. Add cherry tomatoes and olives; toss to coat. Serve relish with chicken.