Although this is quite a long and complicated dish to prepare, the reward of seeing the faces of your guests when they cut into the mousse and out flows the creamy girolle filling must be worth it.
To make the mousse, skin and bone the salmon, cut it into small pieces and then blend in a food processor or blender with the salt until smooth. Add the egg white and blend for a few seconds more until it is well mixed in. Remove from the blender and rub the mixture through a sieve to get rid of any sinews – only by doing this can you be sure of a really fine texture. Set the bowl of salmon on crushed ice, gradually add two-thirds of the cream, then stir in the vermouth and season with salt and pepper and a little nutmeg. Test the mousse – it should be soft and not rubbery and should hold together. If the consistency is not quite right, add a little more cream and test again.
For the filling, prepare the girolles by scraping away any dirt or soil, but do not wash. Put 12 nice, small girolles to one side and cut the rest into 1 cm /½ inch pieces. Bring the Madeira and veal stock to the boil (the veal stock will improve the flavour of the sauce, but if none is available, use extra cream instead). When it has reduced slightly, add the cream and return to the boil. Reduce the sauce until it becomes very thick – as soon as it starts to thicken, it will reduce and thicken very quickly. Remove from the heat and add the diced girolles, stirring in well, and leave the sauce to go cold.
Meanwhile, make the sauce. Bring the Madeira and fish stock to the boil and reduce until only a quarter of the liquid remains. Add the cream and the whole girolles, return to the boil, then turn the heat down to low and gradually whisk in the butter until it has all melted.
When the mousses are cooked, remove them from their moulds an place one on each plate. Spoon the sauce over the mousse, arranging two of the girolles at the side of each plate, and finish with a sprig of fresh dill.
© 1989 Ian McAndrew. All rights reserved.