At the Hang Chieu branch, trays of ingredients are constantly refilled to meet demand. Phuong says no food is kept overnight to ensure freshness.
Every aspect of preparation, from marinating and cooking to assembling each bowl, is handled by Phuong, her husband or their children. Staff members are responsible only for selling and serving customers.
Over the years many people have approached the family to learn the recipe, but they refuse to share the family secret.
"For people of Chinese descent, this is a trade you live by and take to your grave," Phuong explains.