"At that time, all the restaurants had very long menus and it was easy for customers to get lost," Poon said. "Because my restaurant was so small, I could not afford them to take a long time to read the menu, so I designed different set menus labeled A, B, C, D … That became a trend and other restaurants started to follow."

At the time, Cantonese cuisine was prospering in London, driven by a sharp increase in the number of immigrants arriving from Hong Kong.

Celebrity TV chef Ken Hom, author of My Stir-Fried Life, said, "The boom in Cantonese food came from the early immigration of Cantonese immigrants, as they were the first to ... leave a turbulent country racked by poverty－along with the decline of imperial China."

However, the earliest Chinese restaurants in London predate Poon's by a century, according to the British Chinese Heritage Centre. They date to the 1880s when stalls sprang up around London's docklands, where Chinese sailors had settled.

The Limehouse area of east London housed the first Chinatown in the British capital, but it was the International Health Exhibition in the west London district of South Kensington in 1884 that introduced Chinese food to the British public in a big way. This was followed in 1908 by the first recorded opening of a formal Chinese restaurant, in Glasshouse Street, off Piccadilly Circus, which was appropriately named The Chinese Restaurant.