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, approximately 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 the sauce, overlapping slightly.
06 - Top tortillas with half of the beef mixture, 3/4 cup cheddar cheese, and 1/2 cup Monterey Jack cheese. Drizzle 3/4 cup enchilada sauce evenly over the layer.
07 - Repeat with remaining tortillas, beef mixture, and cheeses. Pour remaining enchilada sauce over the top. Sprinkle with any remaining cheese and black olives.
08 - Cover baking dish with aluminum foil. Bake for 20 minutes to heat through and meld flavors.
09 - Remove foil and bake an additional 10–15 minutes until cheese is bubbly and lightly golden on top.
10 - Let casserole stand 10 minutes before serving to set. Garnish with chopped cilantro and serve with sour cream if desired.