Put the cream very cold. Wash the fish and dab dry. Cut off approx. 100 g salmon and cut into small cubes. Mix salmon pieces, 1/4 teaspoon salt and 1 egg white. Cut plaice fillets into pieces.
Mix with 1 teaspoon of salt and remaining egg white. Place both in the freezer for about 30 minutes. In the meantime, clean and wash the spinach and blanch briefly in boiling salted water. Pour spinach onto a sieve and rinse under cold water.
Spread the spinach leaves to form a rectangle (approx. 15x12 cm) so that the leaves are slightly above each other. Puree the salmon cubes and 75 g cream with the cutting stick of the hand mixer. Season to taste with pepper and 2 tablespoons of wine.
Spread half of the salmon farce on the spinach leaves. Cut the rest of the salmon fillet in half lengthwise and lay them on top of each other. Spread with the remaining farce and roll up. Puree the plaice fillets, 300 g cream and 2 tablespoons lemon juice with a chopping stick or in a blender.
Season to taste with pepper. Pour half of the plaice mince into a greased terrine mould (1 1/2 litre capacity). Press a depression in the middle. Place the spinach roll on top, cover with the remaining farce and smooth it down.
Lightly tap the mould on a cloth so that the mixture settles. Cover with greased aluminium foil in the size of the mould surface and close with the lid. Terrine in a hot water bath (z.
B. Grease pan or roaster) in a preheated oven (electric cooker: 200 °C/ gas: level 3) for approx. 1 hour. In the meantime, wash dill, dab dry and chop coarsely. Put the rest of the cream into a high mixing bowl and puree it with the chopping stick.
Season to taste with salt, pepper and the remaining lemon juice, chill. Take the terrine out of the oven and let it cool down. Soak gelatine in cold water. Mix the remaining wine, fish stock and sugar.
Squeeze the gelatine, dissolve at low heat and stir into the stock. Garnish fish terrine with chervil, carrot slices and pepper. Carefully pour the jelly stock over it and let it set. Cut the fish terrine into slices.
Serve with steamed carrot cubes on fresh salalt.