Preheat the oven to 375°F and lightly grease a 9×13 inch baking dish.
In a mixing bowl, combine the shredded chicken, cream cheese, sour cream, 1/2 cup of the Monterey Jack cheese, cheddar cheese, garlic powder, onion powder, and salt.
Stir until the mixture is well combined and creamy.
Spread a few spoonfuls of enchilada sauce across the bottom of the baking dish.
Spoon the chicken mixture evenly into the tortillas, roll them tightly, and place them seam-side down in the dish.
Pour the remaining enchilada sauce over the enchiladas and sprinkle with the remaining Monterey Jack cheese.
Bake uncovered for 25 to 30 minutes or until heated through and the cheese is melted.
Let them rest for about 5 minutes before serving, then top with your choice of garnishes.