'Banh mi' is a Vietnamese sandwich built on a light, baguette-style bread; the name literally means "bread." The French introduced the baguette during the colonial period (mid-19th century), but the filled sandwich as it's known today developed in Saigon in the late 1950s, after Vietnam's 1954 partition brought northern migrants and new fillings to the south.
A traditional banh mi is a toasted or grilled baguette filled with a protein - grilled pork, Vietnamese pork sausage (cha lua), chicken, or tofu - plus pickled carrots and daikon radish, cilantro, cucumber, mayonnaise, chili sauce, and often liver pâté.
Common variations add fried eggs or meatballs, and fillings are often adapted for halal or vegetarian diets. It is sold widely as street food in Vietnam and has become a common menu item internationally.