Begin by preheating your oven to 350°F (175°C). This will ensure your casserole bakes evenly.
In a large skillet, heat the olive oil over medium heat. Once hot, add the diced onion and sauté for approximately 3-4 minutes until it becomes translucent and softened.
Stir in the minced garlic, cooking for an additional minute until you can smell its aroma—this will enhance the flavor of your dish.
Next, add the shredded chicken, diced tomatoes (including their juice), diced green chilies, and taco seasoning to the skillet. Stir well and cook for 5-7 minutes, allowing the mixture to heat through and the flavors to meld together.
While the chicken mixture is cooking, take a separate bowl and combine the softened cream cheese and sour cream. Mix until smooth and creamy, ensuring there are no lumps.
Grease a 9x13 inch casserole dish with a touch of olive oil or cooking spray. Spread half of the chicken mixture evenly across the bottom of the dish to create the first layer.
Dollop half of the creamy sour cream mixture over the chicken layer, spreading it gently with a spatula. Then, sprinkle 1 cup of the combined shredded cheddar and Monterey Jack cheeses over the top.
Repeat the layering process with the remaining chicken mixture, followed by the rest of the sour cream mixture and finish with the remaining cheese on top.
Cover the casserole dish tightly with aluminum foil to keep moisture in, and place it in the preheated oven to bake for 25 minutes.
After 25 minutes, carefully remove the foil and continue to bake for another 10-15 minutes, or until the cheese is bubbling and turns a lovely golden color.
Once baked, remove the casserole from the oven and allow it to cool for about 5 minutes. Before serving, garnish with freshly chopped cilantro for a burst of flavor and color if desired. Serve warm and enjoy the comforting goodness!
Notes
Serve individual portions in bowls garnished with extra cilantro and a dollop of sour cream on top for an eye-catching finish!