5 to 6 potatoes, diced
3 stalks celery, diced
2 carrots, diced
1 lg. onion, chopped
Dice leftover beef
Gravy
Single pie crust
Salt and pepper to taste

Put everything in casserole. Cover with gravy and water, if needed. Cover with pie crust. Bake at 350 degrees for about 1 hour. More of anything can be added to fill casserole.

Idea: Save leftover beef and gravy from meals and freeze until you have enough for casserole.