Preparation Whisk 6 tablespoons olive oil, thyme, rosemary and pepper in 13x9x2-inch glass baking dish. Add chicken breast halves and turn to coat. Cover with plastic wrap and refrigerate at least 4 hours and up to 1 day. Preheat oven to 450°F. Scrape herb coating off chicken and sprinkle chicken with salt and pepper. Heat 3 tablespoons olive oil in heavy large ovenproof skillet over high heat. Place marinated chicken breasts, skin side down, in skillet. Sear chicken until crisp and golden brown, about 5 minutes. Turn chicken and sear 4 minutes on second side. Transfer skillet to oven and bake until chicken is cooked through, about 6 minutes. Whisk lemon juice and remaining 1 tablespoon olive oil in large bowl to blend. Season dressing to taste with salt and pepper. Add arugula to dressing in bowl and toss to coat. Divide mashed potatoes among 6 plates. Top mashed potatoes with arugula salad, then with chicken breasts. Serve immediately.
Preparation Whisk 6 tablespoons olive oil, thyme, rosemary and pepper in 13x9x2-inch glass baking dish. Add chicken breast halves and turn to coat. Cover with plastic wrap and refrigerate at least 4 hours and up to 1 day. Preheat oven to 450°F. Scrape herb coating off chicken and sprinkle chicken with salt and pepper. Heat 3 tablespoons olive oil in heavy large ovenproof skillet over high heat. Place marinated chicken breasts, skin side down, in skillet. Sear chicken until crisp and golden brown, about 5 minutes. Turn chicken and sear 4 minutes on second side. Transfer skillet to oven and bake until chicken is cooked through, about 6 minutes. Whisk lemon juice and remaining 1 tablespoon olive oil in large bowl to blend. Season dressing to taste with salt and pepper. Add arugula to dressing in bowl and toss to coat. Divide mashed potatoes among 6 plates. Top mashed potatoes with arugula salad, then with chicken breasts. Serve immediately.