Chop onion and brown in butter. Add the soups, tomatoes, and broth, and let simmer for 20 minutes.
Debone chicken and shred. Tear tortillas in half and line bottom of baking dish. Then top with chicken, then sauce, and then cheese. Repeat this until you run out of the ingredient, always finishing with cheese on top.
Then bake in preheated oven of 350 degrees F for 45 minutes or until cheese is golden brown.