New Delhi, July 30 -- Scotland is known for whisky, salmon, shortbread, and haggis, a savoury pudding made of sheep's offal, mixed with oats, suet, onion, and spices. In Glasgow, though, curry belongs on that list too. The city has been named Britain's Curry Capital a record four times, and one of its best-known restaurants, Shish Mahal, is widely linked to the story of chicken tikka masala, often called Britain's unofficial national dish.

For Asif Ali, CEO of Groupe Shish Mahal and son of the restaurant's founder, the story has always been much bigger than a single dish. "My father came to Scotland from Pakistan in 1945 with £5 and built something from nothing," he says. "Chicken tikka masala was born here at Shish Mahal in Glasgow...