残羹剩饭
small pieces of food that have not been eaten and are usually thrown away
  We give all our scraps to our cat. 我们把剩菜剩饭都拿去喂猫了。 
 This dish is a great way of using up leftover scraps of roast meat.
 I usually make a stock from any veggie scraps I have.
 Fruit and vegetable scraps can go on the compost heap.
 Restaurant food scraps are now collected for composting.
 I generally use any pastry scraps to decorate the top of the pie.
 See also: scrap noun (SMALL PIECE)