Add to crockpot the chicken . Then season with the garlic, onion powder. Add salt and pepper to taste. Then mix together in a measuring cup the broth, gravy pack and cream of chicken soup until incorporated. Pour the liquid over the chicken in crockpot along with the mushrooms and give it a good mix.Cook on low 5 to 6 hours or high 3 to 4 hours.Once chicken is cooked, remove it from crockpot and shred it. Put the chicken back into the crockpot and stir until all the chicken is covered in the gravy. Let it cook 20 to 30 more minutes and it's done.Serve over rice or mashed potatoes