Preheat the oven to 350 degrees and lightly spray a 9x13 baking dish with non-stick cooking spray. Set aside.
In a large pan or skillet, melt butter and cook onion over medium heat until onions are tender.
Add in shredded chicken and sprinkle with seasonings. Stir and cook for 5-7 minutes.
Next, pour in ¼ cup of enchilada sauce and stir to mix well. Cook for an additional 4-5 minutes.
Put chicken mixture into a large mixing bowl and let cool for a few minutes.
Once cooled, add diced green chiles, chopped olives, and 4 cups of cheese to the chicken mixture. Stir to combine.
Pour a small amount of enchilada sauce in the bottom of the prepared baking dish.
In a large shallow dish, add ¼ cup of enchilada sauce at a time. Dip each tortilla in the sauce, coating both sides, then fill with the chicken mixture, roll up tight and place in prepared baking dish.
Repeat with all tortillas.
Once baking dish is full, pour remaining enchilada sauce over top, sprinkle with remaining cheese, and cover with foil.
Bake in preheated oven for 25-30 minutes, remove foil, and bake for an additional 10-15 minutes or until cheese is melted and bubbly.