Preheat oven to 400 degrees F. Spray a large baking sheet with nonstick cooking spray; set aside.
Add chicken to a resealable gallon sized bag and sprinkle chili powder, cumin, coriander, salt onion powder and pepper on top. Seal the bag and shake to coat the chicken. Heat oil in a large skillet over medium-high heat and cook chicken for 8-10 minutes, stirring occasionally, or until cooked through. Remove chicken from skillet and set aside.
Add bell peppers and onion to the same skillet and cook for 2-3 minutes, or until tender.
Add cooked chicken, cooked vegetables and cheese to a large mixing bowl and mix until well combined.
Wrap the tortillas in a slightly damp paper towel and microwave 6 at a time for 30 seconds to make them easier to fold. Scoop a heaping 1⁄4 cup (approx. 1.7 ounces) of chicken filling onto one half of each tortilla, fold in half and place on prepared baking sheet and gently press down to hold shape.
Bake for 8-10 minutes, or until heated through and cheese has melted. Turn oven to high broil and cook for an additional 1-2 minutes or until tortillas are golden brown.