These marbled chunks of pork shoulder are first simmered to ensure they become tender, and then browned so they develop a flavorful crust.
Place cubed pork, salt, and water in a deep, straight-sided 14-inch skillet. (Water should barely cover pork.) Bring to a boil. Reduce heat, and simmer gently, stirring and skimming foam from the surface occasionally, until water has evaporated completely, 55 to 60 minutes.
Once water has evaporated, pork will begin to brown in its own fat. Cook on all sides, using a spatula to turn cubes and scrape up crisp bits from the skillet, until browned and tender, about 15 minutes. Pork can be refrigerated for up to 1 day. Reheat in a skillet over low heat.
Most butchers will bone and cube a whole pork shoulder for you. This tastes best when served immediately, as the crisp pork edges and browned bits soften with time.