Prepare the oyster mousse by blending 100 g cod or hake flesh with pepper. Add the shelled and cleaned oysters and egg white. Place a bowl over ice cubes and gently fold in the cream with a wooden spatula to set the mousse perfectly.
Fillet the sea bass and divide into 4 portions. Using a thin knife, slice open and stuff each with a spoonful of mousse. Arrange on a sheet of aluminum foil, scatter with chopped shallot, and drizzle with white wine.
In a sauté pan, reduce champagne and sugar until it begins to caramelize, then add the cooking juices from the sea bass. Strain to yield 2 tablespoons of liquid, then stir in double cream off the heat.
Plate the sea bass portions and keep warm.
Gently heat the sauce until the cream nappes (ripples on the surface). Season to taste and generously coat the fish.
Expert tip: Pair with cauliflower or broccoli mousseline for an elegant finish.
Joëlle's insight: This subtle sweet-savory harmony is masterful. Sea bass is pricey and scarce—brill makes an excellent substitute.
