If you have herring in salt or salted brine you need to rinse it first in cold water then let it soak in cold water for 30 minutes. Change the water and repeat 3 times (this is done to reduce the saltiness of the herring).

If your herring comes in a jar, in a light marinade, already rinsed or in an oil-based liquid, it's ready to be used.

Rinse the herring and pat dry with paper towels. Cut into bite-sized pieces.

Cut apples into small dice, dice the onion (you can also cut the onion into thin half-rings). Finely chop dill.

Place onion on a sieve and pour over boiling water (this is done to reduce the raw flavor of an onion, if you don't mind it, you can skip this step).

In a medium bowl, combine sour cream, heavy cream, chopped apples, onion, lemon juice, sugar, and dill. Stir until combined.

Add the chopped herring and still until combined.

Season to taste with salt and pepper (taste the sauce with the herring making sure it won't be too salty), and adjust to your taste with more lemon juice or sugar.

Put in the fridge to chill and for the flavors to meld for at least a couple of hours or overnight. Remove from the fridge about 30 minutes before serving.

Enjoy!