The origin of the dish is disputed. One explanation is that it originated in an Indian restaurant in Glasgow, Scotland, [3][7] but probably from the British Bangladeshi community which ran most Indian restaurants in the United Kingdom.[7] Rahul Verma, a Delhi expert on street food, offered a different explanation, speculating in 2009 that the dish may have originated—probably by accident with subsequent improvisations—in the Punjab and Uttar Pradesh during the last 50 years.[1]
A specific version of the British explanation recounts how a Pakistani chef, Ali Ahmed Aslam, proprietor of the Shish Mahal restaurant in the west end of Glasgow, invented chicken tikka masala by improvising a sauce made from yogurt, cream and spices.[8][9] In 2013 his son Asif Ali told the story of its invention in 1971 to the BBC's Hairy Bikers TV cookery programme:
On a typical dark, wet Glasgow night a bus driver coming off shift came in and ordered a chicken curry. He sent it back to the waiter saying it's dry. At the time Dad had an ulcer and was enjoying a plate of tomato soup. So he said why not put some tomato soup into the curry with some spices. They sent it back to the table and the bus driver absolutely loved it. He and his friends came back again and again and we put it on the menu.[10]
In July 2009 then British Member of Parliament Mohammad Sarwar tabled an Early Day Motion in the House of Commons asking that Parliament support a campaign for Glasgow to be given European Union protected geographical status for chicken tikka masala.[11] The motion was not chosen for debate, nor did Sarwar speak on this subject in Parliament.[12][13]
The historians of ethnic food Peter and Colleen Grove discuss various origin-claims of chicken tikka masala, concluding that the dish "was most certainly invented in Britain, probably by a Bangladeshi chef".[14] They suggest that "the shape of things to come may have been a recipe for Shahi Chicken Masala in Mrs Balbir Singh’s Indian Cookery published in 1961".[14]