The Sourdough Jack is a popular burger offered by the fast-food chain Jack in the Box. It features a beef patty, crispy bacon, and a slice of American cheese, all served on a sourdough bread bun. The unique sourdough bun adds a tangy flavor that distinguishes it from traditional burger buns. In addition to the classic ingredients, the Sourdough Jack is often topped with mayonnaise and ketchup, enhancing its taste. This burger is part of a broader menu that includes various other items, making it a favorite choice for many customers looking for a satisfying meal.