I used to make this the day after we had pot roast with the leftover meat....but we've come to like the pie better than the original meal...so now I just go directly to this pie...since I have lots of meat I make two or three and put a couple in the freezer for later or give one away!
For one pie (9x12 glass dish or 2 qt casserole dish):
2 C cooked beef, cut up
3-4 potatoes, peeled and diced
1 pkg frozen mixed vegetables (10 oz)
1 bottle beef gravy (10 oz.)....you can use the leftover juice from the pot roast, thickened with cornstarch or flour, but the bottled gravy is lower in fat and saves a step.
1 pie crust...I just use AllReady Pie Crust, rolled a little to fit whatever pan you're using.
Peel and dice the potatoes first; cook in a saucepan with a little water until tender.
While the potatoes are cooking, cut up the beef.
Add the vegetables to the cooked potatoes and the meat and gravy; pour into a 9x12 glass pan or a casserole dish.
Roll the pie crust a little to make it conform to whatever dish you are using...tuck under the edges and crimp if there's enough dough. Poke air vents in the top and brush with a little milk so it will brown. Bake at 350 about 45 minutes...
Cooking pot roast....I used to do it in the oven in foil or a cooking bag with some onion soup mix, but it comes out better cooked in a crock pot...with a sliced onion, and a package of soup mix and about 1/2 C water...cook on low 6-8 hours.