Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine shredded chicken, cream of chicken soup, sour cream, and taco seasoning.
Add diced green chilies and milk, mixing until well combined.
Layer half of the crushed Doritos in the bottom of a greased baking dish.
Spread the chicken mixture evenly over the Doritos.
Top with half of the shredded cheese.
Add the remaining crushed Doritos on top of the cheese layer.
Sprinkle the rest of the cheese over the Doritos.
Bake in the preheated oven for 30-35 minutes until bubbly and golden brown.
Remove from the oven and let it cool for a few minutes before serving. Garnish with chopped green onions.