Preheat oven to 400°F.
Cut chicken into thin strips.
Slice onion and peppers into thin strips as well.
Place chicken and veggies in a bowl and top with marinade ingredients and seasoning, tossing well to coat evenly. (If meal prepping or marinading, place in fridge covered until ready to cook.)
Before cooking, spread the chicken and vegetable mixture evenly on a large sheet pan allowing for as little overlap as possible.
Bake for about 15 minutes or until chicken is 165°F internal temperature.
In the last several minutes, place tortillas wrapped in foil in the oven to heat as well.
Remove from oven and rest for about 5 minutes. (Absorb any excess liquid on the pan with a paper towel.)
Serve with your favorite fajita toppings and enjoy!