One night at Beijing - what food street for dinner?

I’ve got an overnight stay in Beijing coming up and I’m looking for a place to hang around in the evening and have a Peking duck dinner at a Sijiminfu or Quanjude (not sure which branch I should go to). I’m tossing between Guijie and Qianmen.

Already seen the Great Wall, Forbidden Palace, Tiananmen Square and the Summer Palace.