Halibut with Sour Cream and Apples

Ingredients for 4:

2 lb halibut (or turbot, or other fatty fish) fillets
0.5 lb thick sour cream
2 medium apples
2 tbsp parsley root
2 tbsp mustard
2 tbsp ground horseradish
1 tbsp lemon juice
Parsley greens and salt on taste

Method:

Bring 3 cups water with 1/3 tbsp salt and parsley root to boil.
Place fish fillets in the boiling water, and set to low heating.
Boil until readiness (for about 10-15 minutes).
Peel and grate apples, mix them with mustard, horseradish, salt, lemon juice, and sour cream.
Blend well.
To serve, place a fish fillet portion on a serving dish, pour the apple-sour cream mix over it, and serve.
You can serve the fish with any potato, rice, or pasta garnish.