Cut the trout fillets into 8 thin slices and flatten evenly between two sheets of cling film.
Cut the sea bass flesh into small cubes, season with salt and white pepper and leave to rest for 10 – 15 mn. Add the egg white and blend the very cold flesh until of a sticky consistency and an even ball shape. Slowly add the cream, soft butter and chopped pistachios.
Position a cylinder of stuffing in the centre of the flattened trout fillets and roll the trout back onto itself. Firmly secure each end and bake in the oven at 95 °C (203°F) for 8 - 10 mn. Refrigerate. Remove the cling film, cut off each end of the roll and brush a little melted butter onto the trout fillet before wrapping in a blanched lettuce leaf.
Cut the Italian tomatoes in half and deseed. Season (salt, pepper, sugar) then add the chopped basil and parsley, unpeeled crushed garlic and the thinly sliced shallots and onions. Mix well. Transfer to a baking tray and bake in the oven at 100 °C (212°F) for approximately 1 hr.
Cut the tomatoes into quarters and remove the seeds. Heat the olive oil in a saucepan then sweat the crushed garlic cloves and the thinly sliced onions. Add the tomato purée, cook for 2 – 3 mn, then add the finely diced tomato flesh and basil. Season, cover, then cook over a low heat for approximately 2 hrs, until the tomato mixture is quite dry. Add the gelatine and leave to cool. Once cooled, add the whipped cream and refrigerate to set. Use two spoons to shape quenelles.
Cut the cucumber into a brunoise. Blend the cream cheese until smooth. Add the softened gelatine then the cream, to thin the cream cheese, and the lemon juice. Finish by adding the cucumber brunoise and season.
Position the trout rolls on a plate. Draw a circle with the tzatziki and wrap a thin slice of fresh cucumber around the outside. Add the mousse quenelle and surround with oven-roasted tomato quarters. Decorate with a basil leaf and drops of virgin olive oil with herbs.