Mom's Beef Potpie

Preheat oven to 425°F (220°C). For Filling: In a large bowl, combine cooked and cubed beef, cubed potatoes and sliced carrots. In another bowl, combine beef gravy, mushroom soup and beef base. Taste, adjusting seasoning as needed. Gently fold gravy mixture into beef and vegetables and pour into a greased 2 1/2-quart casserole. For Crust: Prepare pie crust as directed, except add the garlic pepper or onion powder, if using, to the flour mixture before adding the water. Roll dough out on a lightly floured surface to about 1-inch larger in circumference than the casserole dish. Place on top of beef mixture, roll edges in and crimp. Vent top of crust by making slits with a sharp knife or poking holes with the tines of a fork. Bake for 25 minutes at 425°F (220°C); reduce oven temperature to 350°F (175°C) and bake an additional 15 minutes or until crust is golden and filling is hot and bubbly. Allow to sit for 5 to 10 minutes before serving.