Smear the pork shank with melted butter, salt, black pepper and paprika and place it on top of the potatoes. Pour in 1 cup of red wine 1 cup warm water.
Cover with aluminum foil, put the lid on and put it in a cold oven at the lowest element on moderate heat. Bake for about 2 1/2 hours. Toward the end, remove the foil and lid and return to the oven for it to catch a crunchy crust.
Serve it cut into portions, with a slice of lemon and fresh parsley!