Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine shredded chicken, cream of chicken soup, and sour cream.
Add taco seasoning and mix well until fully incorporated.
Stir in half of the crushed Doritos, cheese, onions, and bell peppers.
Transfer the mixture into a greased casserole dish.
Top with remaining crushed Doritos and cheese.
Cover the casserole with aluminum foil.
Bake for 20 minutes, then remove the foil.
Bake for an additional 10 minutes, or until the cheese is bubbly and golden.
Garnish with fresh cilantro and serve hot.