Preheat the oven to 200°C.
Dry the fish with kitchen paper and stuff the cavity with thyme.
Whisk egg whites until soft peaks form and fold in the salt.
Line a tray with greaseproof paper and spread one-third of the salt mixture on the base.
Lay the sea bass on the salt and cover completely with the remaining mixture.
Bake for 30 to 35 minutes until the salt crust is crisp.
Break the crust with a knife and brush away salt crystals from the fish.
Squeeze lemon juice and drizzle olive oil over the fish.
Mix sliced fennel, dill, orange juice, and olive oil in a bowl.
Stand the salad for 10 minutes then toss in the rocket leaves.
Boil garlic and cream in a pan and reduce the liquid by half.
Remove the garlic bulb and stir in the mashed potatoes.
Mix in the butter and season the mash with salt and pepper.
Serve a quarter of the sea bass with a spoonful of mash and salad.