Preheat the oven to 375°F (190°C).
In a large skillet over medium heat, cook the ground beef until browned, breaking it apart with a spoon, about 5-7 minutes.
Add the chopped onion and minced garlic to the skillet and cook until the onion is translucent, about 3-4 minutes.
Stir in the enchilada sauce, diced green chilies, ground cumin, chili powder, salt, and black pepper. Simmer the mixture for 5 minutes, stirring occasionally. Remove from heat.
Spread a thin layer of the beef mixture on the bottom of a 9×13 inch casserole dish.
Place one tortilla over the beef layer, then spread about one-sixth of the remaining beef mixture evenly over the tortilla.
Sprinkle a mixture of one-third of the cheddar and Monterey Jack cheeses over the beef layer.
Repeat layering with tortillas, beef mixture, and cheese two more times, ending with cheese on top.
Sprinkle the sliced black olives evenly over the top cheese layer.
Cover the casserole dish with aluminum foil and bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let the casserole rest for 5 minutes.
Garnish with chopped fresh cilantro before serving.