Preheat your oven to 350°F (175°C). Prepare a 2-quart casserole dish by spraying it with nonstick cooking spray. This helps prevent sticking and ensures easy cleanup.
In a large mixing bowl, combine the shredded chicken or ground beef, shredded cheese, cream of chicken soup, Rotel tomatoes, sour cream, milk, and taco seasoning. Mix well to ensure all ingredients are thoroughly combined. This mixture is the creamy, flavorful base of your casserole.
Start by spreading half of the crushed Doritos evenly at the bottom of the prepared casserole dish. This will form a crunchy base.
Next, layer half of the chicken or beef mixture over the Doritos. Spread evenly to cover the Doritos layer.
Repeat with another layer of crushed Doritos followed by the remaining chicken or beef mixture.
Optionally, top with an additional layer of shredded cheese, which will create a delicious, melty top layer.
Cover the casserole dish with aluminum foil. This helps to keep the moisture in and prevents the top from burning.
Place in the preheated oven and bake for 35 minutes. If you are doubling the recipe and using a larger 9×13 inch pan, increase the baking time to 45 minutes. This ensures everything is thoroughly heated through and the cheese becomes bubbly.
Remove the casserole from the oven and let it sit for a few minutes before serving. Allowing it to rest helps the layers set slightly, making it easier to serve neatly.
Serve warm. This dish is perfect as a hearty main course and is sure to be a hit with those who enjoy a good, comforting meal with a touch of Mexican