Place the chicken, bell peppers, and onions on each sheet of foil evenly.
Top evenly with seasoning.
Coat with oil spray.
Wrap up the foil packets.
Place the foil packets on the grill and cook for 15 minutes, rotate, and cook for an additional 15+ minutes until the chicken reaches an internal temperature of at least 165*F.
The foil packs can be opened up in the last 10 minutes or so of cooking to vent if preferred.
Serve with warm tortillas.
Notes
I have used olive oil spray regularly with this recipe without an issue, it does have a much lower smoke point than the other oils mentioned above.