Season chicken with salt (optional). Spray nonstick dutch oven or very large sauce pan with cooking spray until well coated. Over high heat, stir fry chicken in pan until it is no longer pink. Remove and set aside.
Respray pan and, over medium heat, sauté onion, bell pepper and garlic until tender.
Return chicken to pan with mushrooms, squash, basil and pepper. Saute for 5 minutes.