Preheat the oven to 350 degrees Fahrenheit and grease a baking sheet with olive oil and set aside.
Cut the chicken, peppers, and onions into thin slices and place them into a large bowl.
Squeeze the lime juice over the chicken, peppers, and onions. Mix until fully coated with the lime juice.
Add your fajita seasonings to the bowl and mix until fully coated.
Place the chicken, peppers, and onions evenly onto the baking sheet.
Bake for 15 minutes.
Once cooked remove from the oven and prepare your fajitas.