In Sai Gon, Chinese-Vietnamese Lan tries to be the perfect daughter, dependable and willing to care for her widowed mother and their banh mi stall. Her secret passion, however, is A Banh Mi for Two, the food blog she started with her father, but has stopped updating since his passing.

Meanwhile, Vietnamese American Vivi Huynh, has never been to Vietnam. Her parents rarely even talk about the homeland that clearly haunts them. Vivi can only daydream about Sai Gon through the eyes of A Banh Mi for Two: her favorite food account dedicated to the street food of the city. Once she secretly begins studying abroad in Vietnam her freshman year of college, Vivi decides to finally unearth the reasons her parents fled their homeland.

When Vivi and Lan meet in Sai Gon, they decide to help each other. Lan shows Vivi around the city, helping her track down locations from old photographs of her mother. Meanwhile, Vivi helps Lan start writing again so she can enter a food blogging contest. As they write and explore the city, their complicated histories catch up with them, and their connection becomes undeniable.