01 - Preheat oven to 375°F. Lightly grease a 9x13-inch baking dish with cooking spray or oil.
02 - Heat olive oil in a large skillet over medium heat. Add chopped onion and cook 2–3 minutes until softened. Add minced garlic and cook 30 seconds until fragrant.
03 - Add ground beef to the skillet. Cook, breaking up meat with a spoon, until browned and cooked through, about 5–6 minutes. Drain excess fat.
04 - Stir in diced green chilies, cumin, chili powder, smoked paprika, salt, and black pepper. Cook 1 minute to blend flavors. Remove from heat.
05 - Spread 1/2 cup enchilada sauce over the bottom of the prepared baking dish. Arrange 4 tortillas over sauce, overlapping slightly.
06 - Top tortillas with half of the seasoned beef mixture. Sprinkle with 3/4 cup cheddar cheese and 1/2 cup Monterey Jack cheese. Drizzle with 3/4 cup enchilada sauce.
07 - Layer remaining 4 tortillas over the first layer. Top with remaining beef, cheese, and another 3/4 cup enchilada sauce.
08 - Pour remaining enchilada sauce over the top. Sprinkle with any remaining cheese and black olives if using.
09 - Cover baking dish with aluminum foil. Bake for 20 minutes to heat through.
10 - Remove foil and bake an additional 10–15 minutes until cheese is bubbly and lightly golden brown.
11 - Let casserole stand 10 minutes before serving to set. Garnish with chopped cilantro and serve with sour cream if desired.