My new fave thing to do with leftover roast is mini pies in a muffin tin. It's so quick and simple cos the meat is already cooked and tender. Fry off an onion and a few garlic cloves with mushrooms, bacon or whatever you fancy. Chuck in the meat (flour it a little) add some wine and a dash of cream, salt, pepper and fresh herbs. Cut puff pastry sheets into quarters and line the tin, spoon in filling then fold pastry over and stab with a fork. Voila!