Have ready an oblong casserole. Preheat the oven to 350.

Run the chicken through the food processor until the pieces are about the size of large rice. Remove the chicken from the food processor into a large bowl and set aside. Process the onion to small chop. Add the onion to the chicken and mix. Process the chiles and tomatoes together until they are just chopped, then add them to the chicken mixture. Mix these ingredients well together. Set aside.

Pour a small amount of the sauce into the casserole. Spread it around.

Using a gas stove, place a tortilla on the burner and turn the gas on high. Use tongs to flip the tortilla when it has started to bubble. Don't let it burn.

Remove the tortilla from the stove top and place it carefully in the corner of the casserole. Do that for three more tortillas so you have overlapping tortilla base.

Put the chicken mixture over the tortillas and spread it out.

Put half the cheese over the chicken and spread this out as well.

Pour half of the sauce over the cheese.

Heat up 4 more tortillas and place them over the cheese mixture. Then top that with the remaining sauce and the remaining cheese.

Bake in the oven about 45 minutes or until the cheese is bubbling.