Polish open-faced sandwiches (also known as french-bread pizzas) are popular street food in the bigger cities of poland. They're known as zapiekanki (plural) or zapiekanka (zah-peeyeh-kahn-kah), which is singular. The word zapiekanka comes from zapiekac, which means "To bake, " And is the polish culinary term for a casserole. Most zapiekanki sandwiches start with french bread, sauted mushrooms, cheese, and ketchup, but there are hawaiian-style zapiekanki with pineapple, greek-style with olives and feta cheese, italian style, and many more. What makes the open-faced sandwich authentic is a thick drizzle of polish ketchup across the top, no matter what cuisine the zapiekanka is trying to emulate.