1. Sprinkle both sides of chicken breast halves with the fajita seasoning. In a large skillet cook chicken in 1 tablespoon of the oil over medium heat for 12 to 14 minutes or until chicken is no longer pink, turning once. Transfer chicken to a serving platter and keep warm.
2. Add remaining oil or butter to skillet. Add sweet pepper strips. Cook and stir for 3 minutes or until peppers are crisp tender. Gently stir in peach or nectarine slices. Cook for 1 to 2 minutes more or until heated through. Spoon pepper strips and peach mixture over chicken.