Preheat your oven to 400°F. Spray a baking sheet with nonstick spray and set aside.
Combine the chili powder, cumin, onion powder, garlic powder, and kosher salt in a small dish.
Place the sliced chicken breasts in a bowl. Pour in 1 tablespoon of olive oil and the spice mixture and toss to coat the chicken.
Heat the remaining 1 tablespoon of olive oil in a large skillet set over medium heat. Add in the seasoned chicken strips, and cook for a few minutes on each side until browned and cooked through. Transfer the chicken to a clean plate.
Heat the olive oil in the same skillet. Add the sliced onion and a pinch of kosher salt and sauté for 3-4 minutes, or until softened. Add in the sliced bell peppers and another pinch of kosher salt. Sauté for an additional 3-4 minutes, until softened. Remove from heat.
Spread the tortillas out on the greased baking sheet. Sprinkle the cheese on one half of each tortilla (2-3 tablespoons per tortilla half). Then, place an even amount of chicken and peppers over the cheese.
Sprinkle any remaining cheese on top and fold each tortilla in half. Rub the olive oil on the tortillas.
Bake for 8-10 minutes until the cheese is melted and the tops of the tortillas are golden brown.
