Begin by preheating your oven to 350°F (175°C), ensuring that it's fully heated before placing the dish inside.
In a large skillet over medium heat, add a splash of olive oil (optional), then sauté the chopped onion and green bell pepper for about 5 minutes or until they have softened and become fragrant.
Meanwhile, in a large mixing bowl, combine the shredded chicken, diced tomatoes with green chilies, cream of chicken soup, and sour cream. Mix well until all ingredients are thoroughly incorporated.
Fold in the sautéed onion and bell pepper mixture, followed by the strips of corn tortillas, ensuring they are evenly distributed throughout the mixture.
Season the mixture with ground cumin, chili powder, salt, and freshly ground pepper, adjusting the seasoning to suit your taste preference.
Carefully pour half of the chicken mixture into a greased 9x13-inch baking dish, spreading it out evenly. Sprinkle half of the shredded cheddar cheese over the top for a cheesy layer.
Layer the remaining chicken mixture on top of the first layer, followed by the rest of the shredded cheddar cheese to create a melty, gooey topping.
Cover the baking dish with aluminum foil to prevent over-browning and bake for 25 minutes. After that, remove the foil and continue baking for an additional 10-15 minutes, or until the cheese is bubbly and has turned a lovely golden brown.
Once finished, carefully take the casserole out of the oven and allow it to cool slightly for about 5 minutes before serving to let the flavors settle.
Notes
Garnish with freshly chopped cilantro for a pop of color and freshness. Serve alongside a side of creamy avocado or a crisp, simple salad.