Rinse trout, cut across in half, sprinkle with lemon juice and season with salt. Pour wine and fish stock into a pot, add fish and cook for about 10 minutes. Take out fish, strain the stock through a fine sieve, set aside.
Fnely chop shallots. Add butter to a saucepan and cook shallots until soft. Add flour to the pan and deglaze with fish stock. Mix well so that there are no lumps left. Add to reserved stock and simmer for approximately10 minutes.
Remove all bones from trout fillets. Puree the fish, add cream. Add fish mixture to the soup. Season with salt and pepper, simmer for about 5 minutes.
Cut smoked trout fillets into small pieces, divide between soup bawls and and pour soup over them. Sprinkle with grated horseradish and decorate with sprigs of dill.