Banh mi, a ubiquitous street food in Vietnam, consists of French bread fully loaded with pate, pork, chicken, pickled carrot, daikon, cucumber and cilantro, topped with a fried egg, hot sauce and mayonnaise.

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itoggle caption Eve Turow for NPR

Each Of These Things Is A Little Like The Other: There's a common ingredient mixed into these dishes ranging from appetizer to dessert. It's the much-maligned condiment, mayonnaise — but you'd never guess it. Trust us. Doreen McCallister/NPR hide caption

itoggle caption Doreen McCallister/NPR