Place salt pork in a medium mixing bowl; add warm water to cover. Soak 1 hour; drain. Repeat soaking procedure.
Place salt pork in a large skillet; add water to cover. Bring to a boil; remove from heat, and drain. Plunge salt pork into cold water.
Dredge salt pork slices in cornmeal. Cook in oil in a large skillet over medium heat until crisp and brown, turning once. Drain well on paper towels. Serve hot with mustard.