Zha jiang mian. A common Northern Chinese dish, sometimes called Beijing-style noodles, made from fermented bean paste. I thought it was decent, maybe good, and pleasantly less stewy/less saucy than when I had the dish in the states.
It's pretty; I'll almost give this picture an excellent. Or did I?
Incidentally, this restaurant is at the corner of Zhishanmen Street and Jingshan W. Street.)