1. Wash the herrings well inside and out in cold water and wipe dry. Sprinkle the stomach cavity with lemon juice and sprinkle the fish with salt inside and out. Leave the herrings to dry slightly, then dip them in flour.
2. Heat the oil and fry the herrings one after the other for 3 minutes each side, turning carefully as the herrings will break easily. Transfer them to a large shallow dish and leave to cool.
3. Bring the vinegar and water to the boil with the bay leaves, peppercorns and allspice. Cut the onions into rings, add to the pan and boil for 5 minutes. Leave the liquid to cool before pouring it over the herrings.
4. Cover the dish and leave to marinate for 24 hours in the refrigerator.
Serve with: roast potatoes.
Cut into chunks or slices pickled herrings can be combined with fresh salad ingredients, gherkins and creamy dressings to make a delicious starter.