Fish in Horseradish Sauce 

2 carrots
2 celery stalks
1 parsley root
1 onion, quartered
5 peppercorns
1 bay leaf
2 teaspoons salt
6 cups water
2 pounds fish fillets (sole, pike, carp or similar fillets)

Sauce:
3 Tablespoons butter
3 Tablespoons flour
3/4 cup prepared horseradish, cream-style
1 teaspoon sugar
1/4 teaspoon salt
2/3 cup sour cream
2 hard boiled eggs

Combine vegetables, dry seasonings and water in a saucepan. Bring to a boil then simmer 20 minutes.  Strain. Cook fish in the strained vegetable stock 6 to 10 minutes, or until fish flakes easily. Remove fish from stock. Arrange on shaped serving platter and cover with plastic wrap. Chill. Strain fish stock and reserve 3/4 cup for horseradish sauce; cool.

For horseradish sauce, melt the butter in a saucepan, then blend in flour until smooth. Add the cooked fish stock gradually, stirring constantly. Cook and stir until the sauce boils and becomes thick and smooth. Remove from heat and stir in horseradish, sugar, salt, sour cream and eggs. Cool for 15 minutes. Pour the horseradish sauce over the chilled fish and garnish with shredded lettuce