Toss pork chop cubes in a bowl with salt, garlic salt, and seasoned salt, and set aside. Heat the bacon drippings in a large skillet, and cook and stir the onions until lightly browned, about 10 minutes.
Melt the butter in a large, heavy saucepan over low heat, mix in the flour, and cook and stir until the roux is golden brown, about 10 minutes. Watch carefully, the roux burns easily. For a darker roux, stir constantly over low heat until it turns a deep reddish brown, 20 to 30 minutes. Raise heat to medium. Mix the cooked onions with drippings and seasoned pork cubes into the roux. Cook until the pork is browned, about 10 minutes, stirring frequently.
Stir in the cabbage, lettuce, green onions, celery leaves, drained spinach, mustard greens, and turnip greens, and cook until tender, about 30 minutes, stirring often. If mixture becomes too dry, stir in reserved spinach liquid, a little at a time as needed.
