1. Rinse the clams and soak them in cold water with coarse salt for 10 minutes.
2. Scrape and rinse the mussels.
3. In a large pot, cook the peeled and chopped shallots in butter for 1 minute. Add the clams and mussels, well drained, parsley, and chervil. Season with pepper and dry white wine. Cover the pot and let the shellfish open over high heat, stirring occasionally.
4. Remove the shellfish and keep them warm in a large covered bowl.
5. Bring the cooking liquid to a boil and let it simmer for 1 minute. Add the cream and mix well.
6. Divide the cream and shellfish into 4 bowls.
7. Garnish with chives and serve hot.