Norway has a long tradition with herring served on bread. Here is a simple recipe where the base is spice-salted herring from jars.
Finely chop garlic and red onion. Mix crème fraîche with lemon juice, salt, sugar and pepper.
Add garlic, red onion and thyme, and taste with salt and maybe a little salt and pepper.
Remove the herring from the jar and add to the new sauce.
Pour this over into a jar or glass and cover with a lid.
The herring should set in the refrigerator for 24 hours before eaten.
The herring can be kept in the refrigerator for approx. 1 week.