This is one of the most popular and traditional dishes of Northern India. It has spread its wings globally since a lot of Punjabi's are settled around the world. I have seen this dish on the menu of various restaurants in the USA and Canada to United Kingdom to down under in parts of Australia. As much as being served up in high profile restaurants, this is still a very much street food too. Various market stalls can be seen serving this homely, wholesome and sumptuous dish.