Chinese food is the world's oyster

While food documentaries often focus on flames, traditional utensils and the hands of craftspeople, Oyster Sauce: A Drop of Umami also turns automated production lines, laboratories and machinery into subjects.

"We wanted to use images to show the beauty of science, industry and order," Li says.

The documentary also follows Chinese culinary influences overseas.

In Thailand, celebrity chef Pichaya Soontornyanakij, known as Pam, opened her family home to the production team for the first time.

Pam's mother is of Chaozhou heritage, and the family's everyday meals combine Thai and Chinese influences. Her mother takes the production team to the market before the family prepares a meal together.

Chinese food culture is expressed not through overt symbols but through ingredients, seasonings and cooking habits.

"When I saw Chinese seasonings in a Thai family kitchen, and saw Thai and Chinese elements blended into their everyday meals, I felt the subtle influence of Chinese food culture," Li says.

Such cultural transmission is not simply a matter of taking a particular Chinese dish overseas. As people migrate, and trade and cultural exchanges expand, Chinese flavors enter new environments, interact with local ingredients and traditions, and develop new forms.

Flavor thus becomes a form of cultural memory. It can cross linguistic boundaries and be passed from one generation to the next.

As the camera moves from the sea to the dining table, the documentary reveals more than how a flavor is created. It shows how Chinese food culture evolves through inheritance and exchange, continuing to find new life as it travels.