Creating these delicious enchiladas is a simple process if you follow these steps:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Mix Ingredients: In a large bowl, combine the shredded chicken, sour cream, half of the enchilada sauce, chili powder, cumin, garlic powder, and onion powder. Mix until well combined. Add salt and pepper to taste.
3. Fill Tortillas: Lay out the tortillas and divide the chicken mixture evenly among them. If using, add black beans and corn for extra filling.
4. Roll Tortillas: Roll each tortilla tightly and place them seam-side down in a greased baking dish.
5. Add Sauce: Pour the remaining enchilada sauce over the rolled tortillas to cover them evenly.
6. Top with Cheese: Sprinkle the shredded cheddar and Monterey Jack cheese over the top, ensuring an even layer.
7. Bake: Place the dish in the preheated oven and bake for 20 minutes or until the cheese is bubbly and golden.
8. Cool Slightly: Remove from the oven and allow to cool for a few minutes before serving.
9. Garnish: Top with fresh cilantro, if desired, for an extra touch of flavor and color.

These steps will guide you seamlessly through the cooking process, leading to mouthwatering enchiladas ready to be devoured!