Preheat the oven to 350°F (175°C).
In a large mixing bowl, combine the shredded chicken, cream of chicken soup, sour cream, milk, chili powder, garlic powder, onion powder, ground cumin, and salt. Mix well until fully combined.
In a 9×13 inch baking dish, spread half of the crushed Doritos evenly on the bottom.
Layer half of the chicken mixture over the Doritos.
Sprinkle half of the shredded cheddar cheese and Monterey Jack cheese evenly over the chicken layer.
Add half of the diced green onions, diced tomatoes, and sliced black olives evenly on top of the cheese.
Repeat the layers: crushed Doritos, chicken mixture, shredded cheeses, and vegetables.
Cover the casserole with aluminum foil and bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden.
Remove from the oven and let it cool for 5 minutes.
Garnish with freshly chopped cilantro before serving.