As the summer dining season winds down, many U.S. cities launch “restaurant week” events, offering reduced menu prices to attract patrons. Yet for ethnic cuisines, diners often turn to a different source for guidance on authenticity: individuals who grew up with the food’s cultural origins.

Vietnamese-born writer Oanh Ngo Usadi reflects on the complexities of defining authenticity, particularly with dishes like pho, Vietnam’s iconic beef noodle soup. She notes that pho varies widely across the country’s regions—from Hanoi’s simpler, more austere version to the sweeter, herb-rich style found in Saigon—and that no single recipe or approach can be deemed the definitive “authentic” pho.

Migration and the availability of ingredients also play a significant role in how ethnic foods evolve. Cooks adapting their traditions in a new setting may substitute rare or unavailable components, sometimes resulting in entirely transformed dishes. Usadi highlights how staple ingredients that originated in the Americas, such as tomatoes and vanilla, fundamentally altered cuisines elsewhere, illustrating that food traditions are rarely static.

Customer preferences further influence these adaptations. Vietnamese cuisine, for example, traditionally features a variety of fresh herbs, some with distinctive or unfamiliar flavors like sawtooth herb and fish mint. To accommodate American tastes, restaurants often replace these with basil or cilantro, which may be more accessible and widely accepted.

Immigrant food traditions often face initial resistance in the United States, as unfamiliar aromas and flavors can be met with hesitation or curiosity. Many immigrant families, including Usadi’s own parents who opened a banh mi sandwich shop in Texas in the 1980s, encountered early challenges but contributed to gradually familiarizing Americans with their cuisines.

The increasing intermingling of different culinary traditions has given rise to numerous fusion dishes. Examples include Tex-Mex fajitas, Korean kimchi burgers, Greek gyro pizza, and even Minnesota sushi, which features dill pickles wrapped in cream cheese and ham. In coastal Louisiana, the arrival of Vietnamese refugees starting in the 1970s led to the creation of Viet-Cajun cuisine, blending spicy crawfish with lemongrass and butter and introducing innovations like boudin egg rolls.

Such culinary hybrids reflect the broader reality of cultural assimilation in America. Rather than a simple loss of heritage, food represents an ongoing process of adaptation and invention. Usadi suggests that when people move from asking “What’s that?” to seeking out an authentic version, it signals a deeper embrace of the cuisine and the communities behind it.

For those seeking genuine Vietnamese dining experiences, Usadi offers a practical tip: establishments that incorporate a number in their name—such as an address or meaningful year—may resonate more closely with Vietnamese naming traditions and indicate a connection to the culture. Conversely, restaurants labeling themselves explicitly as “authentic” may not always guarantee traditional preparation.

Ultimately, the shifting definitions of authenticity underline how ethnic cuisines continue to evolve in America, reflecting both continuity and change as they become woven into the national culinary fabric.