After spending hours cooking pot roast to perfection, we'd eat it and have like half left over (unless I'd cut it in half, then everyone would want more and I'd run out ...). I used to put the left over meat in the fridge and hope the sandwich fairy would make sandwiches or something, but it'd end up just going bad. And I'd feel bad for wasting it. But NOW, the day after pot roast dinner is BBQ sandwich dinner.
Left over pot roast (beef, pork, it's all good)
Bottle of BBQ sauce, more or less depending on how juicy you like it (KC Masterpiece really is the best)
Because I'm lazy, I put the meat in the crock pot, pour on the BBQ sauce and just let it go until it's time to eat (if that will be within an hour I warm up the meat in the microwave first). The meat just gets tenderer and tastier. It's so yummy and amazingly the BBQ meat leftovers actually do get made into sandwiches.