Every once in a while it’s a good idea to check your spices to be sure they haven’t gotten stale. (I just had to replace my ground cumin and chili powder because the old ones had turned flat and flavorless.) The most important lesson in cooking--one that cannot be overemphasized--is to taste everything critically as you prepare a dish. You will be surprised at what a difference it will make.
I serve the following dish with warm tortillas (wrap your tortillas in foil and heat them in the oven at 300 degrees). You can also put some of the sauce from the chicken into your tortilla. Or try serving this dish with rice and spoon some of the tomato sauce over it.