"I want my guests to feel comfortable, like they are at home, in my restaurant, so you would not notice that there are chefs cooking over there," Zhang says, pointing to the kitchen.

He refuses to set up a profile for Yanjintang on food review websites, as he does not want his restaurant to be so popular and crowded that it loses its intimacy.

Zhang starts each day by going to Sanyuanli Market to find seasonally fresh ingredients, while his staff head to the airport at midnight to collect ingredients that Zhang orders from all over the world. He insists using fresh ingredients.

"My principle of making food is using proper ingredients and simply follow the method, without taking shortcuts," Zhang explains.

When he cooks chicken soup with figs, he uses a gauze bag with chrysanthemum to filter the soup - the flower is cold and a bit bitter, which can calm the heat of the chicken soup.

He starts his pigeon soup the night before he serves it, as the bird requires steaming with spring water for at least eight hours. You can also find his signature crawfish dish, with flavors such as huadiao wine ice cream or fermented bean curd.

Zhang is passionate about learning new skills and discovering new dishes. As soon as he learns a new recipe, he cooks it for his guests.

"I have a formula in my head - I know how to calculate different seasonings and what flavor I can get - it's my talent," he says.

"I also have a pot in my head in which I cook the dishes many times before I cook it in real life."