100 ml cream or crème fraîche
about 1 tbsp (or to taste) freshly grated horseradish or horseradish paste
pinch of salt
pinch of sugar
pinch of white pepper
(dash of lemon juice)

Whip the thoroughly chilled cream until soft peaks form. If using crème fraîche, whip it until it is has a light and fluffy consistency. Crème fraîche makes a thicker, sturdier sauce than regular whipped cream. Unlike whipped cream, it can be stored for some time, as it will not "split".

Gently fold in the horseradish and add seasoning to taste. Serve the sauce with poached, baked or fried fish (cold or warm), like poached salmon or fried Baltic herring fillets, or with cold roast beef, smoked ham, etc.

Recipe source: family recipe.