It doesn’t get more mom-and-pop than this little hole in the wall, where authentic northern Chinese fare has replaced a mediocre breakfast spot. The owners started out with a stall at the Richmond Night Market, and they bring their signature Xi’an sandwiches and hand-pulled noodles to a permanent (albeit humble) space. Don’t come looking for swank surroundings or an extensive menu, but do come for those aforementioned sandwiches: braised pork or marinated beef in house-made flatbreadÑthe rich, spicy filling and crispy shell make for a perfect quick lunch. Boiled dumplings have a generous, well-balanced ratio of pork to vegetables. The ÒbiangbiangÓ Shangxi thick noodles have just the right chew. Many dishes are available as vegetarian. Simple, delicious, and cheap.