Place flour in a shallow dish. Coat chicken breasts lightly with flour. Set chicken breasts aside.
In a large skillet, heat 1 tablespoon of the olive oil over medium heat. Add carrot strips; cook and stir for 3 minutes. Add sweet pepper strips, salt, black pepper, and garlic. Cook and stir for 2 to 3 minutes more or until vegetables are crisp-tender. Remove vegetables from skillet; keep warm.
In the same skillet, heat the remaining 1 tablespoon olive oil over medium heat. Add chicken; cook for 12 to 15 minutes or until chicken is tender and no longer pink (170 degree F), turning once. Remove chicken from skillet; keep warm.
In a small bowl, stir together Marsala, chicken broth, and cornstarch; add to skillet along with snipped or dried thyme. Cook and stir until thickened and bubbly, scraping up any browned bits from skillet. Cook and stir for 2 minutes more.
To serve, divide vegetables among 4 serving bowls or dinner plates. Top with chicken. Pour Marsala mixture over chicken. If desired, garnish with thyme sprigs. Makes 4 servings.