duck soup vs kolach

duck soup

noun
  • Something which is easy; a piece of cake. 

  • Used other than figuratively or idiomatically: see duck, soup. 

kolach

noun
  • Type of pastry that holds a portion of fruit or cheese, surrounded by a puffy cushion of supple dough. 

How often have the words duck soup and kolach occurred in a corpus of books? (source: Google Ngram Viewer )