Ingredients:
4-5 chickens (stewing chickens)
7 1/2 lb. of potatoes
2 raw carrots
2 bags frozen peas
4 tomatoes
1/2 c. chopped onion
2 c. celery
2 can of Campbell’s Cream of Chicken Soup
2 can of Campbell’s Cream of Chicken & Herbs Soup
Pastry for 9-inch pie crusts

Preparation:
Cook chicken, debone and skin and cut into chunks. Cook potatoes cut in cubes.

Chop onion, tomatoes and celery add with parsley and tomato chunks. Cook the peas a little. Drain. Mix all of the above in large bowl with heated and cooled soups. Add salt and white pepper to taste.

Line pie pan with pastry and refrigerate until ready.

Pour into pie crust. Put top crust on pie, cut 4 slits in the crust. Brush with beaten egg wash.

Bake on a cookie sheet at 375 degrees for 45 minutes.

Note:
Approximately 4 double batches of pie dough, depending on having top and bottom crusts.

hope this helps. enjoy.
References :

You can buy the rotisserie chicken sometimes just as cheap as buying one and cooking it yourself. I know WalMart has them considerably less than regular grocery stores, much cheaper than purchasing it and boiling it yourself.

I would think you could do fine with six pies.

I use canned veg all and cream of chicken and herb soup (undiluted) with the chicken along with sour cream. I layer it with grated cheddar cheese. I brush the tops with egg wash and bake.

1 chicken per two pies
3 cans of veg all per two pies
1 pint of sour cream per two pies
1 bag of grated cheddar cheese per two pies
1 can of cream of chicken and herb soup per two pies
1 pkg. (2 ea) deep dish pie crust
1 box (2 ea) ready bake pie crust/folded

eggs for egg wash on top of completed pies

Let’s do the math.

3-4 chickens
9-12 cans veg all
3 pints sour cream
3 cans cream of chicken and herb soup
3 small bags grated cheddar cheese
3 two count pkg. deep dish pie shells
3 boxes of ready bake pie crust

Besides if you have salad and biscuits or fruit along with the pot pies they are not going to eat as much.

Mix enough in a large bowl to make two pies at a time.
References :
Experience

I make them this way all the time and people love them and ask for a recipe.

Here’s why:
4 ounces of meat per person would be pretty generous
so for 30 people that’s 120 ounces (7.5 pounds of chicken meat). I’m assuming you’re using the light and dark meat.

If you buy whole chickens most of the weight is bones and fat, about 70% as a round number so you need about 25 pounds of fryeres as a quick guess… which is about 8 to 9 whole birds since each bird weights about 3 pounds each.

Does 8 to 9 chickens make sense?
If you were to serve roasted chickens and each person received a 1/4 of a chicken then 8 chickens would give you 32 servings (quarters). So 8 chickens would be quite generous for a pot pie.

You can actually use fewer chickens since a pot pie contains a lot of other "fillers". So you can probably go down to 6 chickens if you assume 1 whole chicken is enough for 5 people. That’s up to you to decide.
References :