01 - Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish.
02 - Heat olive oil in a large skillet over medium heat. Add onion and cook for 2-3 minutes until softened. Add garlic and sauté for 30 seconds.
03 - Add ground beef, cooking and breaking up with a spoon until browned and cooked through, about 5-7 minutes. Drain excess fat if necessary.
04 - Stir in cumin, chili powder, smoked paprika, salt, and pepper. Mix well to combine spices evenly.
05 - Add black beans and diced green chilies. Cook for 2 minutes to incorporate flavors. Remove from heat.
06 - Spread 1/2 cup enchilada sauce evenly in the bottom of the prepared baking dish.
07 - Layer 4 tortillas over the sauce, overlapping as needed. Top with half the beef mixture, 3/4 cup cheddar cheese, and 1/2 cup Monterey Jack cheese. Drizzle with 1/2 cup enchilada sauce.
08 - Repeat with remaining tortillas, beef mixture, remaining sauce, and finish with both cheeses on top.
09 - Cover with aluminum foil and bake for 20 minutes.
10 - Remove foil and bake for an additional 10 minutes until cheese is bubbly and golden brown.
11 - Let casserole cool for 10 minutes before serving. Garnish with fresh cilantro, green onions, and sour cream if desired.