Preheat the oven to 350. In a large saucepan, heat the butter and oil over medium heat. Add the onions, celery, and carrots and cook until the onions are translucent. Add the flour, stir to combine, and cook for about 2 minutes,
Add the chicken broth, whisking or stirring constantly to prevent lumping. Add the potatoes and cook, stirring occasionally until the sauce has thickened and the potatoes and carrots are tender. Gently fold in the chicken and the green peas and remove from the heat.
Add the bottom crust to your cassserole dish, no need to add butter or oil. You may need to roll out a little to enlarge for your dish! Pour your pot pie mixture in. Place your remaining rolled out pie crust on the top and seal the edges. Add a few slits on the top to release the steam. Bake until golden brown! Serve hot. Leftovers are great the next day. You can also make individual pot pies and freeze before cooking. I do this a lot for my Mom.
Keyword leftovers, pastry, pie, roasted turkey, thanksgiving, turkey, turkey pot pie