Trim the chicken breasts then lay them in a single layer in a glass baking dish.
Sprinkle the taco seasoning over the top of the chicken breast to taste.
Lay your thinly sliced onions and peppers on top of the chicken breast, spread out evenly over the top.
Drizzle the olive oil over the peppers and onions.
Sprinkle cheese over the top of the dish.
Bake at 375? F for 35-45 minutes or until chicken is cooked though and the juices run clear.