Preheat the oven to 375°F (190°C).
Heat olive oil in a large skillet over medium-high heat.
Add the chicken strips to the skillet and cook for 4-5 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 and onion. Cook for 5 minutes until slightly softened.
Add the minced garlic, chili powder, ground cumin, smoked paprika, dried oregano, salt, and black pepper to the vegetables. Stir well and cook for 1 minute until fragrant.
Return the chicken strips to the skillet and stir to combine with the vegetables and spices.
Add the low sodium chicken broth and diced tomatoes to the skillet. Stir to combine and bring to a simmer.
Transfer the entire mixture into a 9×9-inch baking dish, spreading evenly.
Sprinkle the reduced-fat shredded Mexican cheese blend evenly over the top.
Bake in the preheated oven for 20 minutes until the cheese is melted and bubbly and the chicken is cooked through (internal temperature should reach 165°F or 74°C).
Remove from oven and sprinkle chopped fresh cilantro over the casserole before serving.