Called huang you xie (yellowoil crabs), these distinctive decapods are believed to have a much better flavor than their more common counterparts, making them highly sought after among local restaurants.

But for Li, the "secret" that makes Dongguan cuisine attractive to the audience can't just be found in restaurants, where food is cooked in a delicate and complex way, like most Cantonese dishes.

It is the countryside-where locals have inherited the traditions and customs from older generations-that has played a more important role in shaping the distinctive cuisine practices of Dongguan.

Eating zongzi, a Chinese snack made from glutinous rice stuffed with different fillings and wrapped in leaves, is a traditional custom across the nation during the Dragon Boat Festival.

In Dongguan, rural residents have turned the practice of wrapping the tasty treats into an art. They collect leaves from pandan trees, cutting the stick-studded edges of the leaves. Then they select strips of leaves with similar lengths to weave into shapes like baskets or bags, which are filled with rice and yolk to make the pandan-leaf zongzi.

"The native population in Dongguan has been essentially stable (many residents are locally employed) in recent decades, thus making it possible to preserve their traditional cuisines," says Li.

Gao Hao, director of the documentary, reveals that the delicacies are not the only "protagonists" in food-themed documentaries, and sometimes the stories of the people behind the dishes are more interesting.

"For us, the main rule for making a good documentary is to always tell a good story," he adds.