In a small mixing bowl, whisk together the olive oil, lime juice and fajita marinade.

Place the chicken in a storage bag or bowl and pour the marinade on top.

Let the chicken marinade in the refrigerator for at least 30 minutes.

Preheat a grill over medium high heat. Clean the grill grates thoroughly and rub them with oil to keep the chicken and veggies from sticking to the grill.

While the grill is preheating, cut each of the peppers into quarters and remove the seeds and membranes and slice the onions into thick rings.

Remove the chicken from the marinade and gently shake off any excess marinade.

Place the chicken, peppers and onions on the grill. Grill for 15-20 minutes, flipping them all halfway through the cook time until the chicken is cooked through (reach an internal temperature of 165 degrees F and the peppers and onions are browned).

Remove the chicken, peppers and onions from the grill and let the chicken rest for 5-10 minutes.

Warm the tortillas on the grill for 1 minute per side while the chicken is resting.

Slice the chicken, peppers and onions. Serve over the warmed tortillas with your favorite fajita toppings and enjoy!