A Beijing restaurant owner congratulated her "old friend" and one-time customer Joe Biden on Monday after the U.S. Democratic candidate emerged victorious in a tightly fought U.S. presidential election, and invited him back to try some pork liver. The publicity following Biden's visit nine years ago boosted business for quite a while, with many customers coming in and asking for the "Biden set," said owner Yao Yan, 66. Biden had dined on noodles and steamed buns for lunch in August 2011 at the Yaoji Chaogan restaurant in the Chinese capital's Drum Tower district, during an official visit to Beijing as U.S. vice president.