Preheat oven to 375°F. Spray an 11x7-inch baking dish with cooking spray (a 9x13-inch dish may be used but the casserole will be thinner).

Rinse and drain the black beans and drain the diced green chiles.

In a large bowl, combine 2 cups diced or shredded chicken, ½ teaspoon ground cumin, ½ teaspoon ground coriander, ½ teaspoon garlic powder, 1 tablespoon of the chopped fresh cilantro (reserve the remaining 1 tablespoon for garnish), the rinsed black beans, and the drained diced green chiles. Mix until evenly combined.

Pour and spread half of the 10-ounce can of red enchilada sauce over the bottom of the prepared baking dish.

Arrange four (6-inch) tortillas over the sauce, overlapping as needed to cover the surface.

Spread half of the chicken mixture evenly over the tortillas.

Sprinkle half of the shredded Mexican blend cheese (1 cup) over the chicken.

Dollop half of the sour cream (½ cup) in small spoonfuls over the cheese and gently spread or leave as small dollops, as you prefer.

Spoon the remaining enchilada sauce evenly over the top.

Arrange the remaining four (6-inch) tortillas over the sauce, overlapping as needed.

Spread the remaining chicken mixture evenly over these tortillas.

Cover the dish with a lid or aluminum foil and bake for 30 minutes in the preheated oven.

Remove the cover, sprinkle the remaining shredded cheese (1 cup) over the top, and bake uncovered 5–10 minutes more, until the cheese is melted and bubbly.

Remove from the oven, top with the remaining sour cream (½ cup) and the reserved chopped cilantro, and let stand 10 minutes before cutting and serving.