Kumpir - Turkish Street Food Style Jacket Potato - Kumpir is a popular Turkish street food (It is especially popular in Istanbul) and it is the Turkish version of a Jacket Potato. In this recipe the inside of the Potato is mashed with Butter and Cheese to make it creamy whilst the skin remains intact and slightly crispy. It is then topped with fillings such as Kisir, Black Olives, Corn, Turkish Sausage (Sucuk), Sour Cream, Pickles and other toppings.