Creating delicious Chicken Enchiladas is a breeze if you follow these steps:

1. Preheat Your Oven: Set your oven to 350°F (175°C) to prepare for baking.
2. Cook the Onions: In a skillet, heat a tablespoon of olive oil over medium heat. Add the diced onions and sauté until translucent.
3. Combine the Filling: In a large bowl, mix the shredded chicken, sautéed onions, black beans (if using), and half the cheese. Season with salt and pepper to taste.
4. Warm the Tortillas: To make rolling easier, warm the tortillas in a dry skillet for about 30 seconds on each side until pliable.
5. Fill the Tortillas: Spoon the chicken mixture onto each tortilla. Roll them tightly and place seam-side down in a greased baking dish.
6. Add Sauce: Pour the enchilada sauce evenly over the rolled tortillas. Sprinkle the remaining cheese on top.
7. Bake: Place the baking dish in the preheated oven and bake for 25-30 minutes or until the cheese is bubbly and golden.
8. Garnish and Serve: Once baked, remove the enchiladas from the oven. Let them cool for a few minutes, then garnish with fresh cilantro. Serve with sour cream on the side.

Following these steps will help you create an incredible dish that is sure to impress your family and friends.