The duck impressed former United States' president George H.W. Bush when he stayed in China in the 1970s, who then recommend it to former US secretary of state Colin Powell.

Jinyang-style fried-and-boiled pork is another of the restaurant's signature dishes that originates from Shanxi province. "It's not a dish that you can replicate at home," says Ma.

To make the dish, four eggs are added to half a kilogram of sliced pork and mixed together before they are quickly slid into a frying pan of semi-heated oil. The oil is then filtered off before cucumber and agaric are added.

"The key is to pour a little vinegar into the pot before the pork is plated, so that you can just smell a hint of sourness in the dish - but not taste it," says Ma.

Shanxi cuisine is famous for its different types of noodles, and all of Jinyangfanzhuang's pastry dishes are based on Shanxi recipes.

Wenxi shortcake is said to have been given its name by empress Dowager Cixi after she tried the snack while she received good news about her enemies being defeated.

The cake is crispy and made up of countless paper-thin layers. "The secret is that the dough has to be marinated in oil for 24 hours," says Ma. "That's also the trick to making the one strip of noodles that's dozens of meters long."