Combine fresh lime juice, minced garlic and salt in a bowl. Add chicken breasts that have been lightly pounded to tenderize Coat breasts with juice mixture, cover and refrigerate for an hour. Spray nonstick skillet with cooking oil spray and heat over medium high heat. Remove chicken from marinade (discard marinade). Add chicken to skillet and saute chicken about 3 minutes per side or until cooked through. Remove chicken from skillet. Add more cooking spray if needed. Add onions and stir fry for 2 to 3 minutes, add peppers and continue to stir until lightly crisp and tender. Cut chicken into strips. Cover vegetables and chicken to keep warm. Sprinkle with chopped cilantro. Divide among four plates and serve with warmed flour tortillas.