Preheat the oven to 400 degrees Fahrenheit (204 degrees Celsius).
Grease a 9x13-inch baking dish with non-stick cooking spray or a light coating of oil.
In a large mixing bowl, combine the sliced chicken, bell peppers, and onions.
Drizzle the olive oil over the chicken and vegetable mixture.
In a small bowl, whisk together the chili powder, cumin, garlic powder, smoked paprika, salt, and pepper.
Sprinkle the spice blend over the chicken and vegetables, tossing thoroughly to ensure an even coating.
Spread the mixture into a single even layer within the prepared baking dish.
Bake for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165 degrees Fahrenheit (74 degrees Celsius).
Remove from the oven and sprinkle the shredded cheese evenly over the top.
Return to the oven for 5 minutes, or until the cheese is melted and beginning to bubble.
Garnish with chopped cilantro and serve immediately.