Remove the bay leaf. Poach one double chicken breast in water, salt, cumin, and a bit of chile powder. Skin and shred the meat. Spray a casserole dish with non-stick cooking spray. Cut the corn tortillas in wedges and put a layer of them in the casserole dish.
Sour cream is classic.
Add a bit of sauce, depending on how much Mexican flavor you want in the casserole itself. Repeat with the tortillas, chicken, and cheese, etc. Finally, make a custard with eggs and milk. Pour custard over the ingredients and refrigerate overnight. Be sure there is ample custard to soak into the tortillas.