It's hard to know what to do with leftover roast. You can eat it in sandwiches or make a stew, but sometimes you need something different. My grandma's method was to make Meat Pie.
Meat Pie isn't strictly a pie. I'm not sure it's even loosely a pie, but it's a great way to use up leftover roast ingredients. It's essentially a soup on the bottom with biscuits or dumplings floating on the top. My grandma used to just make Bisquick biscuits, but my mom found a homemade dumpling that we use now. It's a simple, hearty dish stemming from the necessity of making a bit of leftover meat stretch into an entire meal. As a pastor's wife, my grandma's grocery budget was not large.
It's a great recipe because it's flexible, depending on what you have leftover from your pot roast. Bare bones, you only really need leftover meat and gravy to make this, but you can also add in leftover onions, carrots and potatoes.
The rich broth gets its flavor not only from gravy, but also smashed roasted onions and carrots that were from your pot roast. If you have them, they deeply enhance the flavor profile of the broth. Added to this is leftover roast chunks and bites of carrot and potato. The dumpling batter is dropped onto the top, where it cooks in the steam generated by your simmering "soup." A delicious way to turn boring leftovers into a satisfying meal.