Cook, bone and chop chicken and place in a large mixing bowl.
Dice and cook onion in a bit of butter till somewhat tender, then add to chopped chicken.
Add other ingredients and mix well.
Spray a deep baking dish with non-stick cooking spray then cover the bottom with torn pieces of corn tortillas. Spread a layer of chicken mixture over the tortillas till covered then add another layer of torn bite size pieces of tortillas. Continuing layering ending with the chicken mixture on top.
Generously sprinkle parmesan cheese on top of the last layer.
At this point it may be frozen or will keep in the refrigerator for several days. You may also bake it now.
If frozen let it thaw before baking. If rrefrigerated let it sit out about 30 minutes before putting it in a hot oven.
Bake in a preheated oven at 350 for about 45 minutes until sides bubble and top is nicely browned. Let it sit about five minutes before serving.
I serve this dish with a salad of lettuce, chopped green onions and fresh tomato. Just before serving I open and rince the sauce off a can of Ranch Style Beans (original) and drain well. At the last minute toss beans and salad with a few Frito corn chips (small size)with your favorite Catalina dressing. (I use fat free or reduced fat)
I have never been able to make enough to have left overs! My family loves it.