I guess I found a pearl among insider tips. "Found" is the right word, because I had to search for it. No. 59 is actually a small alleyway. A couple of meters inside I encountered a blackboard with the menu in Vietnamese and a door with a narrow staircase (mind your head), leading upwards into a tale from "1001 Nights".
The restaurant is equipped with low tables, blue divans, pillows and a tasteful decor which radiates the flair of the middle east. At least how the rest of the world would imagine the Middle East. The music however was western - hits from the nineties, and the staff is really friendly.
Somehow the Casbah was not prepared for foreign customers - so they translated the menu, which consisted of 3 items, to English and wrote it down on a block of paper: Fried squid, chicken in tamarind sauce and stir-fried beef. I picked the chicken, because I have a thing for tamarind sauce, plus one lime juice.
The food was probably part of a small lunch menu for office workers from the area, because it was ready pretty fast. I expect a restaurant with only 3 items on the menu to be exceptionally delicious. And indeed, they did not disappoint me. The chicken and the (partially pickled) vegetables had a fine, but spicy taste to them that I have not encountered so far - in perfect harmony with the sweet and sour deliciousness of tamarinds.
The furnishing of the Casbah suggests that it is rather a dinner bar than a restaurant, so next time I intend to return with friends in the evening, to check on the mentioned middle eastern menu and the shishas. I also forgot to check out the view from the roof, but that's okay since there will definitely be a next time!