Preheat oven to 375°F (190°C). In a large bowl, mix the shredded chicken, cream cheese, sour cream, green chiles, cumin, and salt until creamy and well combined.

Spread 1/2 cup of the enchilada sauce in a 9x13-inch baking dish. Arrange 6 tortillas over the sauce, overlapping as needed. Spread half the chicken mixture on top, scatter half the black beans if using, then sprinkle 1/2 cup cheese. Spoon about 3/4 cup more sauce over the cheese. Repeat with the remaining tortillas, chicken mixture, beans, and sauce, then top with the rest of the cheese.

Cover with foil and bake for 20 minutes. Remove foil and bake another 10 to 15 minutes, until bubbly and golden. Let rest 5 to 10 minutes before slicing.

Slice into squares and serve with sour cream, chopped cilantro, avocado, and lime wedges.