Wet hamburger

Islak hamburger (English: wet hamburger) or Taksim hamburger is a type of Turkish street food consisting of a hamburger soaked in tomato sauce. It is then typically served with mayonnaise. It is particularly popular around the area of Taksim Square in Istanbul.

History
Restaurant chain Kristal Büfe claims that founder Ahmet Yazıcı invented the islak hamburger accidentally after hastily trying to prepare a burger with boiling tomato sauce. The burgers were already being stored in open cases allowing them to be quickly served hot despite becoming soggy from the resulting steam.