Combine tomato, cucumber, green pepper, purple onion & jalepeno pepper in a small bowl & set aside. Combine cumin & pepper. Rub all sides of chicken breasts with this. Place a large cast iron skillet over medium high heat until hot. Add chicken & cook 6 min. On each side or until tender. Remove from skillet, reserving drippings in skillet. Set chicken aside.
Add vinegar to pan drippings & cook 2 min, stirring constantly. Pour over reserved vegetable mixture, tossing well. Thinly slice each chicken breast diagonally across grain & arrange on individual serving plates. Serve with reserved vegetable mixture. Garnish each serving with cherry tomatoes & basil.