In a medium bowl, mix 1/4 cup olive oil and 2 tablespoons poultry seasoning*.
Pour this mixture between the skin and the meat on the breast and thigh sides of the chicken, then run the rest on the outside.
Place the breast side up in a roasting pan or dutch oven and roast in the oven at 400°F for 20 minutes per pound or until the internal temperature is 165F.
Allow the chicken to cool, then remove all the meat from the carcass and rough chop it into 1" pieces.
Prepare Filling
Use the dutch oven you used to roast the chicken with the drippings still in it to make the pie filling.
Over medium heat add carrots, celery, onion, and peas to the drippings from roasting the chicken. Simmer for 10 minutes, stirring occasionally.
Add salt, pepper, garlic powder, onion powder, Italian seasoning, and flour. Stir and continue simmering on medium heat for a minute or two.
Slowly pour the chicken broth and cream into the dutch oven and raise the heat to medium-high heat. add the cooked chicken back in, once the pot pie filling starts to bubble, remove from heat.
Assemble and Bake
Preheat the oven to 425°F.
Roll out the bottom crust layer of the sourdough pie crust and place it in a greased and floured pie dish.
Add the filling and place the top layer of sourdough pie crust over the filling. Trim, then seal/crimp the edges of the crusts and poke holes in the top with a fork or make a few cuts with a knife before baking.
Bake the pot pie for 20 minutes uncovered, then cover with foil and bake for another 15 minutes or until the crust is golden brown.
Allow the pot pie to cool for about 10-15 minutes before serving.
Notes
This chicken pot pie is delicious leftover the next day and will keep in the fridge in an airtight container or covered with plastic wrap for up to 5 days.*Make your own poultry seasoning: 2 teaspoons salt, 1/2 teaspoon black pepper, 1 teaspoon onion powder, 1 teaspoon garlic powder, and 2 teaspoons Italian seasoning.