Lift the sole fillets away from the bone. Blanch and skin the tomato and dice it. Peel and chop the shallots. Wash the mushrooms, cut the heads into strips, and reserve the stalks.
Take the head, the skin, and the bones of the sole and cover with water. Cook this with the white wine, the shallots, and the mushroom stalks for 20 minutes.
Put the egg yolk in the top of a bain-marie over a low flame. Add one spoonful of water, whisk and work in the clarified butter.
Add salt and pepper and whisk the mixture to obtain a smooth paste.
Strain the fish stock through a conical sieve. Place the fillets of sole, the mushrooms, and the tomato in a dish or casserole, then pour the fish stock over them. Let cook over low heat until the stock boils.
Drain the fillets of sole, reserving the fish stock. Take out the tomato and mushrooms.
Reduce the stock until there are only a few spoonfuls left. Beat the whipping cream until it is light and fluffy, using a whisk or a mixer. Add the fish stock and the cream to the sauce.
Cook the pasta for 5 to 6 minutes in boiling salted water. Arrange the noodles, with the tomato and mushrooms on an ovenproof serving dish. Place the fillets of sole on top.
Cover with sauce. Place under the broiler for 2 to 3 minutes until it browns slightly.