Lois Clary works at a San Francisco robotics firm, where long hours move her to regularly order in from a sandwich shop. The place is peculiar, but the food is amazing, especially the sourdough bread. When the brothers who run the shop leave town, they eagerly bestow their sourdough starter on their "number one eater." Though Lois is hapless in the kitchen, she soon masters baking so well her loaves catch the attention of her employer's in-house chef and, eventually, an elite invite-only farmers market.