Saigon Sisters, Chicago

The Nguyen women have been in the food business a long time. In Vietnam, matriarch Suu and her mother expanded an open-market grocery into a formidable supplier to local embassies. When her own daughters grew up—those would be the eponymous sisters Mary Nguyen Aregoni and Theresa Nguyen—they developed a menu of modernized Vietnamese sandwiches to sell at a popular booth in the Chicago French Market. In 2009, the three women finessed the concept into a slightly upscale, sit-down showcase for the pungent flavors of pho spices and nuoc cham.

Since being named Best New Restaurant of 2011 by Chicago Magazine, critics, food lovers, and travelers attempting to find Asia using only their sense of smell have poured in. At lunch, they come for bánh mì, the classic Vietnamese combination of fresh bread, zippy herbs and veggies, and savory meats. Chicago Magazine named the Hen House—a candy-for-lunch combination of caramelized chicken with peanuts—one of the best sandwiches of 2012. Thrillist chose the Wagyu-beef-filled VBQ version for its list of "Five Sandwiches You Must Eat," whereas the fluffier, palm-size bánh bao caught the attention of Crain's Chicago Business in a roundup of downtown's best sandwiches.