Kathi rolls are a popular street food in Kolkata. They are made with a paratha (Indian flatbread) that is filled with a variety of fillings, such as chicken, mutton, paneer (Indian cottage cheese), or vegetables. The filling is usually marinated in spices and then cooked on a griddle. The paratha is then wrapped around the filling, creating a delicious and portable meal. Kathi rolls are often served with a side of chutney or ketchup.