This is a recipe given to me about 5 years ago, but since then I have seen similar recipes on this site under "Jalapeno Chicken Casserole" titles or such:

Chicken Tortilla Casserole

4 Whole Chicken Breasts
1 dozen Corn tortillas cut into 1" strips
1 Large can of Ortega diced chilies
1 can Cream of Mushroom Soup
1 can Cream of Chicken Soup
1/2 cup milk
1 finely chopped onion
1 # Tillamook cheese

Steam in foil, grill, or broil your chicken breasts until about 90% done. I like the foil because it leaves in so much moisture and flavor.
Spray your casserole dish with Pam, and preheat oven to 400 degrees.
Combine milk, soup, onion and cheese.
Starting with a small amount of soup-cheese mixture on the bottom of the casserole dish, arrange 3 layers in the casserole in this order:
tortillas, chicken, chiles, soup-cheese mix. Bake in a 400 degree oven for 1 hour and serve with a nice salad with a Salsa flair!

Enjoy!