In a food processor, process the fish into a very smooth purée. Add the cream, egg, and nutmeg and process until smooth, scraping the bowl a couple of times. Season with salt and pepper. With two tablespoons, shape the fish dumplings with about 45 ml (3 tablespoons) of the mixture for each and drop them in a pan of salted simmering water. Cook, six at a time, for 3 to 4 minutes. Drain and keep warm on a plate.
In a saucepan, brown the shallot with the lobster carcass in the oil. Deglaze with the wine. Add the butter and sprinkle with the flour. Cook for 1 minute, stirring constantly. Add the milk and bring to a boil, stirring constantly. Simmer gently for about 3 minutes. Strain. Season with salt and pepper.
Divide the sauce among four shallow plates and top with the dumplings. Garnish with chervil.
For a traditional presentation, pour the sauce over the dumplings in a serving dish and brown in the oven under the broiler.
Traditionally, the dumplings were made with pike. To simplify the recipe, we opted for the haddock. For a finer texture or if you use a fish with a lot more bones, such as pike, strain the fish mixture through a sieve.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.