Preheat the oven to 375°F and grease a 9x9 inch baking dish.
Heat the olive oil in a small saucepan over medium heat. Add the chili powder, cumin, garlic powder and oregano and stir for 30 seconds until fragrant, then whisk in the tomato sauce, chicken broth and salt. Simmer for 5 to 7 minutes until slightly thickened.
In a large bowl, mix the cream cheese and sour cream until smooth. Stir in the chicken, green chiles, cilantro and 1/2 cup of the enchilada sauce.
Spread the chicken mixture into the baking dish and pour the remaining enchilada sauce evenly over the top.
Sprinkle with the monterey jack and cheddar.
Bake for 20 to 25 minutes until bubbly and the cheese is melted and lightly browned.
Let it rest for 5 minutes, then top with the avocado, green onions and dollops of sour cream.