|Herrings/Similar amount of other fish||8|
|Onion||1 , sliced|
Clean the fish, removing the heads and tails, but leaving the roes inside.
Pack into a casserole.
Sprinkle with the seasonings and pour over the vinegar.
Cover and bake for at least 1 1/2 hours in a slow oven.
Longer cooking improves the flavour and makes the bones soft, so that they can be eaten.
Leave in the dish to become cold, and serve with some of the strained liquor as a sauce.