Preheat the oven to 350 degrees and spray a 9x13 baking dish with non-stick cooking spray. Set aside.
In a large cast iron skillet or frying pan, over medium heat, melt butter and add onions, jalapenos and seasonings. Stir to combine.
Cook until onions and peppers are tender. Add in shredded chicken and stir to combine. Let cook for 2-3 minutes.
Add diced green chilies and about ¾ of the can of enchilada sauce to the meat mixture. Stir to combine and cook until heated through.
Pour the remaining enchilada sauce in the bottom of the baking dish and spread around to cover the bottom of the dish.
Next, add a layer of flour tortillas over the enchilada sauce followed by ⅓ of the chicken mixture and sliced olives, and top with a cup of shredded cheese.
Place another layer of tortillas over the cheese followed by another ⅓ of the chicken mixture, sliced olives, and top with more shredded cheese.
Add a third layer of tortillas, the remaining chicken mixture and the remaining shredded cheese and sliced olives.
Cover with aluminum foil and bake for 30 minutes or until the cheese is hot and bubbly.
Remove foil and place under the broiler for 5 minutes.