Preheat the oven to 415°F and line a large rimmed baking sheet with foil. Spray with nonstick spray.
Place the bell peppers and onions onto the pan and bake for 3 to 5 minutes, while you slice the chicken.
Then place the chicken on the pan and drizzle the olive oil over the top and sprinkle on the Fajita seasoning. Toss to coat.
Bake for 20-25 minutes, or until the chicken is cooked through and the vegetables are fork tender. I like to stir the vegetables half way through, and drain off any excess liquid from the pan around 15 minutes. If you like your vegetables a little more browned, bump up the heat to 425°F half way through. Add salt and pepper to taste.
Enjoy the fajita chicken inside a tortilla, on top of a bed of rice or salad if you’re watching your carbs. Top with your favorite toppings.
Marinate: If you have extra time, I like to marinate the chicken with the olive oil and Fajita seasonings for about an hour beforehand. You can also buy a fajita sauce (Frontera makes one) to marinate the chicken in. If you’d like to add more vegetables, feel free to add mushrooms and squash as well.Wrap the tortillas in foil and place in the pan the last 5 minutes, to warm them up.