Place sweet potato in a medium saucepan with enough water to cover. Bring to a boil, and cook 15 minutes, or until tender. Drain, mash, and set aside.
Prepare dry corn bread mix according to package directions. Crumble, and set aside.
Place sausage in a large, deep skillet. Cook over medium high heat until evenly brown. Drain, and set aside.
Melt butter in the skillet over medium heat, and stir in celery, green onions, onion, and parsley. Cook and stir until tender, about 10 minutes.
Return cooked sausage to skillet, and mix in oysters and their reserved liquid. Allow oysters to cook about 5 minutes before stirring in crumbled cornbread and mashed sweet potato.