If you want you can buy chicken in the can to use. If you are fixing for a single person this isn't too bad but to fix a large batch it is very expensive to go this route.
I don't really recommend dried onions as you would need tolet the dish set for several hours to hydrate the onion. Fresh is best.
It depends on when I make it but for the most part Iprefer garlic powder over minced garlic.
Once mixed together let set for at least an hour to let ingredients and spices blend together.
Also onion and celery really need to be diced as small as possible for a better consitancy if using as a sandwich spread.
If you want shredded fresh carrots can also be added.
This is good on sald, or as a sandwich.