Put on to boil in a large kettle, fill with cold water, enough to
completely cover the tongue; keep adding hot water as it boils down so
as to keep it covered with water until done. Keep covered with a lid
while boiling and put a heavy weight on the top of the lid so as not to
let the steam escape. (If you have an old flat iron use it as a weight.)
It should boil very slowly and steadily for four hours. When tongue is
cooked set it outdoors to cool in the liquor in which it was boiled. If
the tongue is very dry, soak overnight before boiling. In serving slice
very thin and garnish with parsley.