How to make a turkey pot pie with this, that, and whatever else:
Start with enough cut-up cooked turkey meat to fill the bottom of a 9 x 13 inch pan. Cover with any combination of the following: leftover gravy and/or milk plus a little flour, leftover chopped vegetables, sliced mushrooms, carrots sliced or chopped small, frozen peas, salt and pepper, dried onion, garlic powder (just a bit), thyme, even a bit of cheese. Think small pieces of everything, and just enough liquid to keep things moist. Stir it around a bit. Bake at 350 degrees until hot and bubbly; time it so you reach that point about half an hour before dinner. Turn the oven up to 375 degrees.
You can make a from-scratch biscuit crust, but a can of refrigerated crescent rolls works well too. If you're using crescent rolls, do all your messing with the can before removing the hot turkey mixture from the oven. Take the pan out; check to see that it has enough liquid; and cover it with the unrolled dough (or rolled, or cut in circles if you're using homemade biscuits). It doesn't matter if it's all in one piece or not. Leave some gaps, or vent it with a sharp knife. Return the pan to the oven and let it bake through.
Let sit a few minutes before serving. One pan serves about six people, depending on how much filling you put into it.