Cut, strip, and tear three bunches of turnip and two of mustard greens. Peel and cube turnip roots to cook or not.
Put greens in a clean stoppered sink, sprinkle with salt, cover with water, and agitate to knock off sand and other debris. Repeat until thoroughly clean. Drain thoroughly and load into a pot on medium heat. Add about two cups of water or light stock, a chopped white onion, and a pound of sliced bone-in ham or smoked turkey tail.
Reduce heat and cover. Stew, stirring occasionally, for at least two hours. Adjust salt, add a little pepper, and let sit before serving.