Anyone who arrives in Lang Son Province could find it difficult to say no to Lon quay dish.
Lon quay Lang Son is delicious for many reasons,
however, the main specific taste of the dish comes from the unique
flavor of a kind of leaf called "Mac mat" (meaning "sweet leaf"). The
leaf is soaked with spices, fish sauce, glutamate, flavoring powder,
then stuffed into clean pig belly and placed on reverted furnace. Pig
is fried the spread with watery honey so as to make the skin turn
golden and brittle, and pork is soft and sweet-smelling as finish.