In a large skillet over medium heat, spray with cooking spray and add the ground beef. Cook until browned and crumbled.

Add diced onions and cook for 2 to 4 minutes until softened. Stir in salsa, green chilies, and taco seasoning. Remove from heat.

Spray a 9x13 inch baking dish with cooking spray. Spread a thin layer of enchilada sauce on the bottom.

Place 4 tortillas in the dish, tearing if necessary to fit. Layer with ⅓ of the beef mixture, ⅓ of the enchilada sauce, and ⅓ of the cheese. Repeat layers twice.

Cover with foil and bake at 375°F for 25-30 minutes until bubbly.

Remove foil, sprinkle remaining cheese on top, and bake uncovered for an additional 10 minutes until melted.

Allow to rest for 5 minutes before serving. Garnish with chopped cilantro if desired.