Shed the pegs, wash them and cut off the heads. Pat dry and drizzle with lemon juice. Turn in flour. Heat some oil in a pan and fry the herrings one after the other until golden brown on both sides. Depending on the size, this takes 3 to 4 minutes per page. Allow to cool and place in a sufficiently large container with a lid.

Cut the onions into rings. Boil the white wine vinegar with the water, sugar, salt and the remaining spices for about 5 minutes. Remove from heat, add the onion rings to the hot marinade and let cool.

Pour the marinade over the herrings and leave to stand, covered, in the refrigerator or a cool cellar for at least 2 to 3 days.