Shāobing Jiā Lǐjī (烧饼夹里脊) is the sesame flatbread with pork tenderloin: a baked, layered shāobing split open and packed with a grilled or fried strip of lean pork. The angle is a lean protein in a rich-textured bread, which sets up a specific risk. Tenderloin has almost no fat, so it dries fast and goes stringy if overcooked or held; the shāobing is crisp and flaky but not juicy on its own. The sandwich works when the pork is cooked just through and stays tender and the sauce bridges the two, and it fails when the meat is dry and the dry bread has nothing to carry it.
The build is split-and-fill, meat cooked to order. A plain savory shāobing, laminated with an oil-flour paste and baked with a sesame crust so it opens into flaky layers, is cut along its seam into a pocket. Pork tenderloin is sliced or pounded thin, often marinated and sometimes lightly battered, then quickly grilled or pan-fried so it colors outside while staying just done within. It goes into the warm bread with a brush of savory bean or chili sauce, and usually a little fresh scallion, coriander or shredded pickle to cut the richness of the fried meat. Done well the pork is hot, tender, and seasoned through, the sauce moistens the cut layers without sogging the crust, and the sesame shell stays crisp around a clean, savory center. Done poorly the failure modes are specific: tenderloin cooked too long or held on a line turns dry and chewy and the dry bread amplifies it; a heavy batter fried hard makes the filling a greasy crust with little meat under it; too much sauce or a long wait between frying and filling collapses the shāobing into a soft, oily wad.
It shifts by how the pork is treated and how it is dressed. A thin marinated cutlet grilled fast stays leanest and cleanest; a battered, deep-fried strip is richer and crunchier; some stalls slice the meat thin and pile it, others use one larger cutlet. The cutting garnish slides from a few scallion threads to a full handful of pickle and herb, which lightens a fried filling considerably. The plain shāobing itself, the egg-filled shāobing, and the meat-baked-in ròu shāobing are each their own preparation and deserve their own article rather than being folded in here. What holds shāobing jiā lǐjī together as a category is the contrast: a crisp layered sesame bread split warm around a lean, just-cooked pork strip, with sauce doing the work of tying them together.