Preheat oven to 425 F . Spray a large sheet pan with non-stick cooking spray, set aside.
In a small bowl, whisk together the seasonings; chili powder, cumin, paprika, garlic powder, onion powder, red pepper flakes and salt and pepper to taste. Set aside.
In a large bowl combine olive oil, chicken, bell pepper, onion and seasonings . Toss to combine.
Spread chicken, bell peppers and onion into an even layer on baking sheet . Roast until chicken is fully cooked and bell peppers/onions reach desired tenderness ( approx. 10 – 15 min depending on the thickness of the chicken strips) careful not to overcook the chicken.
Wrap tortillas in aluminum foil and warm up in the oven for last 5 min. of cooking time.
Remove fajita mixture from oven and pour off any extra juices from cooking. Squeeze juice from fresh lime over fajita mixture and sprinkle with fresh cilantro. Serve filling warm in warm tortillas and top with optional toppings (like sour cream, cheese, salsa or guacamole).