Wash the meat in cold water. Place in a deep saucepan and cover with cold water. Add 1 sliced carrot, 1 sliced onion, a bay leaf and 5 peppercorns. Bring to the boil and simmer until the meat is tender (2 - 3 hours). It is ready when the rough skin starts to bubble. Remove from heat, drain and remove the rough skin which should peel away easily. Slice and serve.
If tongue is served cold, it should be cooled in the liquid it was cooked in.
Tongue can also be prepared in a slow cooker. Follow directions as per above, but increase cooking time to 4 - 6 hours depending on make and size of slow cooker.