Rinse tongues, place in saucepan and cover with cold water.
Add peeled onion, garlic, bay leaf and salt.
Bring to a slow boil, cover, reduce, heat, and simmer gently for at least 2 hours or until tongues are tender.
Remove tongues, skin them and remove any bone and gristle from roots.
Strain stock and reserve.
To make Raisin Sauce, return 1 cup stock to a clean saucepan, add raisins and brown sugar.
Bring to the boil and stir in wine mixed with cornflour to a smooth paste.
Add salt and pepper to taste.
Reduce heat and stir constantly until sauce thickens.
Add tongues and simmer for 20 minutes.
Serve tongues either whole or sliced lengthways in Raisin Sauce.