Another idea for next time--
Keep a bag in the freezer for leftover brisket, steak, etc. Grind it for filling for things like kreplach, meat blintzes, etc. If there's gravy, definitely save that, in small bags, for recycling into future sauces and fillings. That's pure gold in your freezer!
I cannot stand to throw away any kind of meat. I'm not a vegetarian, but it feels to me like it's one thing to kill animals and eat them, another to kill them and throw them in the garbage. Just a personal thing. So I try to use all the leftovers somehow or at least give it to the dog and cat.