Preheat your oven to 350°F (175°C) and lightly grease a 9×13-inch baking dish.
In a large bowl, combine the cooked chicken, cream of chicken soup, sour cream, diced tomatoes with green chilies, taco seasoning, and half of the shredded cheese. Mix until well combined.
Take half of the crushed Doritos and spread them evenly on the bottom of the greased baking dish.
Pour the chicken mixture over the Doritos, spreading it out evenly.
Top the casserole with the remaining crushed Doritos and the rest of the shredded cheese.
Sprinkle the chopped green onions on top.
Bake in the preheated oven for about 25-30 minutes, or until the cheese is melted and bubbly.
Let the casserole sit for a few minutes before serving to allow it to set.
Variations & Tips
For a spicier kick, you can use spicy Nacho Doritos or add a splash of hot sauce into the chicken mixture. If you’re looking to cut down on dairy, swap out the sour cream for Greek yogurt. This recipe is also flexible with veggies—throw in some corn, black beans, or diced bell peppers for added color and nutrition.