Prepare the oven and sauce: Preheat your oven to 350°F (175°C). While the oven heats, get your batch of red enchilada sauce ready.

Cook the filling: In a large sauté pan over medium-high heat, warm the oil. Add the diced onion and cook for about 3 minutes, stirring occasionally until slightly softened. Stir in the diced chicken and green chiles, seasoning generously with sea salt and freshly cracked black pepper. Continue cooking the mixture for 6–8 minutes, stirring now and then, until the chicken is fully cooked. Add the rinsed and drained black beans, stirring to combine everything evenly. Remove the pan from heat and set it aside.

Assemble the enchiladas: Create a simple assembly line with tortillas, enchilada sauce, the chicken mixture, and shredded cheese. For each enchilada, place a tortilla on a flat surface and spoon about 2 tablespoons of enchilada sauce across the tortilla. Add a generous portion of the chicken and bean mixture in a line down the center, then sprinkle about 1/3 cup of cheese over the top. Roll the tortilla up tightly and place it seam-side down in a greased 9 x 13-inch baking dish. Repeat with the remaining tortillas and filling. Once all enchiladas are arranged in the dish, pour any leftover enchilada sauce over the top, and sprinkle with any remaining cheese.

Bake the enchiladas: Bake uncovered in the preheated oven for 20 minutes, or until everything is heated through and the tortillas are slightly crispy on the edges. Transfer the dish to a wire rack once done.

Serve: Serve the enchiladas right away while they’re hot and gooey. Add your favorite toppings such as chopped cilantro, diced red onions, avocado, sour cream, and crumbled cotija cheese. Enjoy every bite!