01 - Set oven to 375°F.
02 - Heat olive oil in a large skillet over medium heat. Add diced onion and sauté 3 to 4 minutes until softened. Add garlic and cook 1 minute more.
03 - Add ground beef to the skillet. Break apart with a spatula and cook 6 to 8 minutes until browned and fully cooked. Drain excess fat if necessary.
04 - Stir in cumin, chili powder, smoked paprika, salt, and black pepper. Incorporate black beans, diced green chiles, and tomato sauce. Simmer for 3 to 4 minutes, then remove from heat.
05 - Lightly grease a 9x13-inch baking dish. Spread ½ cup enchilada sauce evenly on the bottom.
06 - Arrange 4 tortillas over the sauce, tearing to fit if needed. Evenly spread half of the beef mixture over tortillas. Sprinkle with half of the cheddar and Monterey Jack cheeses. Drizzle with ½ cup enchilada sauce.
07 - Repeat layering with remaining tortillas, beef mixture, most of the remaining cheese, and the rest of the enchilada sauce. Reserve some cheese for topping.
08 - Cover dish with foil. Bake for 20 minutes.
09 - Remove foil, sprinkle reserved cheese on top, and bake uncovered for 10 to 15 minutes until bubbly and golden.
10 - Allow to rest for 10 minutes before slicing. Garnish with cilantro, avocado slices, and serve with sour cream if desired.