Lightly oil or olive oil spray a 9×13 inch baking dish
Place first 5 ingredients (cilantro through chicken) in pot on top of stove and poach chicken breasts until cooked (about 20 minutes).
Remove chicken breasts, discard remaining water, cilantro and onion and set aside to cool.
When cool, shred into small pieces. This can be done the day before.
In large mixing bowl, gently combine shredded chicken, hummus, sour cream, cumin, green onion, 1 and 1/2 cup cheese.
Season to taste with salt and pepper.
Cover bottom of baking dish with enchilada sauce.
Cover with even layer of tortillas, breaking into pieces as necessary.
Top with even layer of chicken mixture followed by a layer of enchilada sauce.
Repeat until chicken is used up and end with layer of tortillas.
Top with enchilada sauce, cover and bake in preheated oven for about 35 minutes.
Uncover, top with remaining cheese and black olives. Bake about 5-10 minutes or until cheese melts.