Put chicken in a large kettle with enough water to cover. Add tomato sauce plus add water to each can and rinse remaining sauce from sides of can. Bring to a boil.
Reduce heat to medium. Add garlic, salt, and mushrooms. Cook until chicken is almost done, 20-30 minutes.
Spray a large baking dish with non-stick spray. Layer in the following order until all used:
Juice from chicken
Top with chicken pieces. Bake for 30-45 minutes. Baste with chicken broth every 15 minutes, if needed. Turn chicken after 20 minutes.