Preheat your oven to 400°F (200°C).
In a large bowl, combine olive oil, chili powder, cumin, garlic powder, onion powder, salt, and pepper.
Add the chicken breasts to the bowl, tossing to coat them in the spice mixture.
Arrange the marinated chicken breasts in a baking dish, surrounded by sliced bell peppers and red onion.
Bake the chicken and vegetables for 25-30 minutes until the chicken is cooked through.
Sprinkle shredded cheddar cheese evenly over the top of the chicken and vegetables.
Return the dish to the oven for an additional 5-7 minutes until the cheese is bubbly and slightly golden.
Remove from oven and let it rest for a few minutes before serving.