A zapiekanka (Polish pronunciation: [zapʲɛˈkaŋka]; plural: zapiekanki, pronounced [zapʲɛˈkaŋkʲi]) is an open-face sandwich made of half of a baguette or other long roll of bread, topped with sautéed white mushrooms, cheese and sometimes other ingredients, and toasted until the cheese melts. Served hot with ketchup, it is a popular street food in Poland. With its origin dating back to the 1970s, the zapiekanka is associated with the austere times of Poland's Communist regime, but it has enjoyed renewed demand in the 21st century, which has also brought a wider range of varieties.