Matjes herring filling
400 g (14.11 oz) matjes herring
200 g (7.05 oz) creme fraiche
3 g (0.11 oz) chives
3 g (0.11 oz) fresh dill
Salt to taste

Matjes herring
400 g (14.11 oz) herring
100 g (3.53 oz) distilled white vinegar
200 g (7.05 oz) sugar
6 g (0.21 oz) salt
300 g (10.58 oz) water
50 g (1.76 oz) onions
2 g (0.07 oz) allspice powder
2 g (0.07 oz) cinnamon powder
1 g (0.04 oz) clove powder
5 bay leaves

Kavring bread
120 g (4.23 oz) wheat flour
240 g (8.47 oz) whole grain rye flour
235 g (8.29 oz) porter beer
95 g (3.35 oz) dark molasses
10 g (0.35 oz) fresh yeast
5 g (0.18 oz) salt
1 g (0.04 oz) caraway seeds
1 g (0.04 oz) fennel seeds
1 g (0.04 oz) anise seeds

Instructions

Matjes herring
Freeze the herring for at least 72 hours. Thaw the herring completely.
Chop the onions into a small/medium dice.
Boil the water, sugar, salt, onions and spices for 5 minutes. Let it cool.
Add the distilled white vinegar and chill to 5-8° C (46.4 degrees Fahrenheit).
If the herrings are big, slice into 2 cm bites.
Add the herring to the pickling liquid and refrigerate for 20 hours.

Kavring bread
Grind the spices and mix with the beer and yeast.
Add the rest of the Components and knead the dough for 5 minutes.
Grease a loaf pan with soft butter and then flour it lightly.
Add the dough to the loaf pan and let it rise for 1 hour.
Heat the oven to 175° C (347 degrees Fahrenheit).
Bake the bread for 30-40 minutes or until a thermometer reads 98° C (208.4 degrees Fahrenheit) in the centre.

Matjes herring filling
Strain the matjes herring. Put the sieve over a bowl so the excess liquid drains off. Pick out the bay leaves.
Chop some of the chives. Leave some for the garnish.
Chop the dill.
Cut the matjes herring into smaller pieces.
Mix the matjes herring, dill, chives and creme fraiche until just incorporated. Salt to taste.

Assembly
Put the kavring bread and the butter in a food processor. Mix to a crumbly texture.
Place a 10 cm pastry ring on some baking paper. Pour some bread crumbs in the pastry ring and press hard with a spoon or with a tamper. Pour some more bread crumbs in and press down. Continue with this step until you have approximately 1 cm pressed bread crumbs.
Pour 1/4 of the matjes herring filling into the pastry ring, on top of the kavring bread crumbs.
Press gently and smooth the top.
Put 60 g (2.12 oz) of lump fish roe on top and smooth out.
Take the pastry ring off carefully. Use a wide spatula to transfer the cake to the serving plate.
Put some chives on top for decoration.