Clean the herrings, rinse, drain, season inside and out with salt, pepper and a few drops of vinegar and Worcestershire sauce each, turn in flour to the other side and fry in hot oil until crispy, turning several times.
Boil the water heartily with vinegar, onion slices and the spices listed, cool, season a second time (the marinade should be spicy and pleasantly sour), pour over the fried herrings and leave everything together to marinate for about 2 days with the lid closed and refrigerated.
Tip: Stock up on a range of high-quality spices – it pays off!