The German street food made from sausage topped with curry ketchup is currywurst.
Currywurst usually consists of sliced pork sausage covered with a tomato-based curry sauce or ketchup and dusted with curry powder. It is commonly served at German snack stands with fries or a bread roll. Regional versions differ: some use a bratwurst-style sausage, while others use bockwurst or beef sausage, but the curry-sauce preparation gives the dish its name.
The dish is widely associated with Herta Heuwer, who is credited with inventing it in West Berlin in 1949. She reportedly obtained ketchup or similar ingredients and curry powder from British soldiers, combined them with spices, and began selling the result from a stand in Charlottenburg. Currywurst became especially popular among workers rebuilding postwar Berlin.
A common mix-up is treating currywurst as a particular sausage variety. It is better understood as a prepared dish: the sausage can vary, but the defining feature is the curry-seasoned ketchup or sauce. It remains especially popular in Berlin, Hamburg, and the Ruhr region.