Remove the core from the cabbage using a sharp knife.
Place the cabbage cored side down in a large pot, add the 2 cups of vinegar and enough water to cover the cabbage.
In a pot make the rice according to package directions. Once rice is done move it to a large mixing bowl and add the butter and pepper.
Stir well to combine thoroughly.
Take a cabbage leaf and split it down the center removing the tough rib part. If the leaves are large, slice the half of the cabbage leaf in half again.
Cover with foil. Bake for 1 1/2 hours.