Also inexpensive, as the going rate around town for this is RMB 4, or just over 60 cents US. Finally, when I asked the guy how late they were open he said, "Late. I'm usually here until morning."
Tasty, cheap, and open really late. Can't go far wrong there, right?
But I'll post about it when I find my notes.
(I found a couple of posts from other people with photos of the food from other places, but nothing about the specific restaurant where I ate. http://www.beijingboyce.com/2009/05/22/street-eats-donkey-burgers-in-bray-jing/ and http://chinablog.se/?p=197)