Heat oven to 375°F. Lightly spray 13 x 9 inch glass baking dish with cooking spray. In small bowl, mix enchilada sauce and salsa, and reserve 1/4 cup of the mixture.
In a large bowl, mix remaining enchilada sauce mixture, ground beef, sour cream, 1/4 cup of the green onions and taco seasoning mix. Spoon reserved 1/4 cup reserved enchilada sauce in bottom of baking dish.
Arrange 8 tortilla pieces over sauce, overlapping as necessary. Spoon half of the chicken mixture over tortillas, then sprinkle with 2/3 cup of the cheese. Repeat layers.
Cover with foil Bake 30 to 35 minutes or until hot.
Layer tortilla chips, tomato, olives, remaining 1/4 cup green onions and remaining 2/3 cup cheese over the top of the casserole. Bake uncovered 5 minutes later.
Let stand 10 minutes before serving. Garnish with cilantro.