Rinse the gutted and scaled fish with cold water and pat dry. Then salt and pepper inside and out, then turn in flour. Heat the oil in a pan and fry the fish on both sides for about 5 minutes until golden brown and set aside.
To prepare the brew, salt and sugar are dissolved in the mixture of vinegar and water and brought to the boil in a saucepan. Cut the onions into slices and add to the stock with the bay leaf and the preserving spice. Bring the whole thing to the boil again.
Put the fish in a bowl and pour the stock over them. Once the whole has cooled, the bowl is placed in the refrigerator for 2-3 days to marinate.
Whether at lunchtime with a potato salad or in the evening with bread and butter, let it taste you.