Make the pickle broth: Mix the sugar, water, vinegar, and spices. Heat it so the sugar melts, then cool it down to room temperature.
Make sure your jar is clean and washed in very hot water.
Remove the skin from your onions and cut them into slices. Wash and peel your carrot. Cut it into slices.
Rinse the herring in cold water and slice it into 1-inch wide pieces.
Layer the herring pieces in the jar with the sliced onion and carrot. Pour over the cooled spice broth. The herring is ready to serve after 2 days.
Notes
Pickled herring stores in the fridge for a couple of weeks. (+4C, 39F)If you don't have spirits vinegar use white wine vinegar. The amounts are: ¾ cup water, ¾ cup white wine vinegar. Reserve around 6-10 herring pieces/person if you serve it with potatoes, boiled eggs, bread, and sauce.