This is street food at its finest. 肉夹馍 (ròujiāmó), sometimes called (but never by me!) the "Chinese hamburger", is comfort/fast food from 陕西 (Shǎnxī or Shaanxi) province that has spread all over China. As with hamburgers the constituent ingredients can vary, but in general include:
1. Stewed fatt...
I only just put up that little photo essay and then this community gets created.