Make a roux:

Cook 1/2 cup flour with 1 stick of butter on medium heat for 15 minutes.
Gradually add slowly, whisking in gradually:

3 3/4 cups chicken broth
1 tsp. or more salt as desired
1 1/2 tsp. Bell's Seasoning, or more to taste
1 1/2 tsp. onion powder

Meanwhile, peel, cube and cook 2 1/2-3lb. potatoes until tender.
Thaw 1 -1 1/2 lb. peas
Poach 2 1/2-3 lb. chicken ( just under a boil on medium heat for about 10 minutes)

Combine all ingredients into a casserole dish, or freeze some for later if this quantity is too large.

Top it with either a pie crust, or some bisquick biscuits or for a gourmet version, some puffed pastry you buy in the supermarket, following thawing and rolling and cooking directions.

Heat in an oven until the crust is cooked. This could take some time, but will vary with what you chose for a top crust.