Preheat the oven to 375°F (190°C).
Heat olive oil in a large skillet over medium-high heat.
Add the chicken pieces and cook for 5-6 minutes until lightly browned but not fully cooked through. Remove chicken from skillet and set aside.
In the same skillet, add the sliced red, green, and yellow bell peppers, onion, and minced garlic. Sauté for 5 minutes until vegetables are slightly softened.
Return the chicken to the skillet with the vegetables. Sprinkle chili powder, ground cumin, smoked paprika, dried oregano, salt, and black pepper over the mixture. Stir well to coat evenly.
Add the chicken broth and diced tomatoes to the skillet. Stir to combine and bring to a simmer. Cook for 3-4 minutes until the chicken is cooked through and the liquid has slightly reduced.
Transfer the chicken and vegetable mixture to a 9×9 inch casserole dish and spread evenly.
Sprinkle the reduced-fat shredded cheddar cheese evenly over the top.
Bake in the preheated oven for 15 minutes until the cheese is melted and bubbly.
Remove from oven and garnish with chopped fresh cilantro before serving.