WINE AND DINE: Pickled and deboned yellow croaker [Photo provided to Shanghai Star]

This secret recipe has won Zhuang Yuan Lou numerous customers, and it sells more than 10,000 yuan ($1,621) of zao food for take-away every day. Zhuang Yuan Lou’s signature zao dishes are pig’s feet, pork knuckle, pig palms and hairtail fish.

Usually, I hate to chew oily pork knuckles on a sultry summer’s day, but when it’s cooked in the zao style, the dish gives me a totally different experience, as it is less greasy and has a nice refreshing aftertaste.

Similarly, the hairtail fish loses its original odor, and has a light zao smell. Soaked in the sauce, the fish is chewy and pleasantly seasoned. Another dish I would recommend is tuofeng, literally camel’s hump, actually made of pig palms but so-called because they resemble mini camel humps.

Because only limited tuofeng can be obtained from each pig, not every diner will be lucky enough to savor it.

"Because of the limited production, supply is always short," says Lu Yong, manager of the restaurant.

As the demand for take-away food continues to rise, Zhuang Yuan Lou started to offer a home delivery service in October 2013.

"This is why we are looking to expand our outlet network in different locations," said Mao Wanjuan, financial director of the restaurant.

According to Mao, their goal is to have a branch in each district. Although the recipe has remained almost unchanged over the years, Lu says, as people become increasingly concerned about healthy food, they are gradually making zao food with less salt.

"We declare our products contain zero additives," says Mao.