Salmon Terrine with Sauternes and Dill

Grease a 1-litre terrine mould thoroughly with the softened butter and line with cling film, leaving an overhang. Set aside in the refrigerator.

Bloom the gelatine: submerge the sheets in a bowl of cold water and leave to soften for 5 minutes.

Combine the Sauternes and fish stock in a wide, shallow saucepan over medium-low heat and bring to a bare simmer, around 75°C. Add the salmon cubes and poach for 6–8 minutes until just opaque throughout — check with a meat thermometer that the centre reaches 63°C. Transfer the salmon to a plate to cool and reserve the poaching liquor.

Increase the heat and reduce the reserved poaching liquor until approximately 80 ml remains, about 8–10 minutes. Remove from the heat, squeeze the excess water from the bloomed gelatine, and stir it into the hot reduced liquor until fully dissolved. Set aside to cool to room temperature.

Transfer two-thirds of the cooled salmon to a food processor. Add the egg yolks, Dijon mustard, lemon zest, lemon juice, salt, white pepper, and cayenne. Blitz to a smooth purée, scraping down the sides once.

With the processor running on low speed, pour in the cold double cream in a slow, steady stream until fully incorporated and the mousse is silky. Do not overprocess. Transfer to a large mixing bowl.

Fold the cooled gelatine-Sauternes mixture into the mousse with a spatula until evenly combined, then fold in the chopped dill and tarragon.

In a clean bowl, whisk the egg whites with a pinch of salt to soft peaks.

Fold one-third of the whites into the mousse to lighten it, then gently fold in the remaining whites in two additions, keeping as much volume as possible.

Flake the reserved one-third of poached salmon into large pieces by hand — do not shred. Fold these flakes gently through the mousse so visible chunks remain throughout.

Pour the mousse into the prepared terrine mould and smooth the surface. Fold the cling film overhang over the top.

Refrigerate for a minimum of 6 hours, or overnight, until fully set and firm to the touch.

To unmould, fold back the cling film, place a serving board over the mould, and invert. Peel away the cling film carefully. Slice with a warm, sharp knife wiped clean between each cut, and serve each slice with a small quenelle of crème fraîche and watercress dressed with the remaining lemon juice.