Preheat the oven to 375 degrees and lightly grease an 8x8 baking dish.
Heat a skillet over medium heat and cook the diced onion for 3 minutes until it softens.
In a mixing bowl, combine the shredded chicken, black beans, corn, cooked onion, chili powder, and cumin.
Spread 1/2 cup of enchilada sauce across the bottom of the baking dish.
Arrange half of the tortilla quarters in a single layer over the sauce.
Spoon half of the chicken mixture over the tortillas and sprinkle with 3/4 cup of cheese.
Repeat the layers with the remaining sauce, tortillas, chicken mixture, and another 3/4 cup of cheese.
Pour the remaining enchilada sauce over the top and finish with the last 1/2 cup of cheese.
Bake for 25 minutes until the cheese is melted and the edges bubble.
Remove from the oven and let it rest for 5 minutes before garnishing with cilantro.