Preheat oven to 400°F (200°C). Spray an 18 by 13-inch rimmed baking sheet with non-stick cooking spray.
For the seasoning: In a small mixing bowl whisk together chili powders, cumin, paprika, coriander, 1 ½ tsp salt and ½ tsp pepper, set aside.
For the fajitas filling: Spread bell peppers and yellow onion onto baking sheet.
Top with chicken strips then sprinkle garlic and seasoning evenly over chicken strips.
Drizzle olive oil over top then toss everything to evenly coat. Spread into an even layer working to keep chicken from overlapping.
Roast in preheated oven, tossing once halfway through cooking, until veggies are tender and chicken has cooked through, about 18 - 25 minutes (test a few of the larger pieces to make sure they are 165 in the center).
Wrap tortillas tightly in foil and warm in oven during last 5 minutes of fajita filling cooking.
Drizzle lime juice evenly over top of the chicken fajita filling, sprinkle with cilantro and more salt to taste and toss to coat.
Serve filling warm in warm tortillas with desired toppings.
