Over medium high heat, add the butter and minced onion to a large pot. Sauté until the onion is translucent.
Next, add in the flour and whisk until boiling. Once boiling, whisk for 30 seconds.
Then add in the broth, milk and water and whisk until smooth.
Once liquids are incorporated, add in the chicken gravy mix, salt and pepper, continue to boil until it begins to thicken up.
When your mixture is thick, add the chicken, peas & carrots and hash browns to the mixture in the pot. Stir to combine.
Grease the bottom of a 9 inch pie plate and place one of the pie crusts in the bottom.
Pour the pot pie filling into the crust-lined pie plate and spread evenly.
Top the mixture with the second pie crust and pinch the edges to seal. To prevent burning, cover the edges of the pie crust with foil.
Bake at 350° for a total of 1 hour. You will leave the foil on the edges for the first 3 minutes. Then remove the foil and bake for an additional 30 minutes.
Once the crust is golden brown, remove the pie from the oven. Allow the pie to cool for 5-10 minutes before serving.
Enjoy!