Cut off and discard tough stems and discolored leaves from greens. Wash greens thoroughly in cold water several times; drain slightly. Set aside.
Place hog jowl in a large Dutch oven; add water to cover. Bring to a boil; reduce heat, and simmer 45 minutes.
Add greens and salt; cook over low heat until steam begins to form. Reduce heat; cover and simmer, stirring occasionally, 1 1/2 hours or until greens are tender. Add water, if needed.
Serve turnip greens and hog jowl with poached eggs and cornbread, if desired.