1. If using, put mushrooms and onion in bottom of crock pot.
2. Place frozen chicken in crock pot.
3. Combine soup (use 2 cans if you want to have more gravy) and milk and pour over chicken.
4. Combine the stuffing mix, seasoning packet and water and spoon mixture over chicken.
5. Cover and cook on low 8- 10 hours.
6. Enjoy!