Melt the butter in a frying pan, add the remaining ingredients , brown well, with a spoon distribute the contents of the pan onto the seasoned and briefly seared sea bass fillets. Gratinate for a few minutes in the oven at 200 degrees C.
Boil the potatoes in salted water, drain off the water and sieve the potatoes , add the remaining ingredients and stir together well.
Place the aubergines whole in the oven for 30 minutes at 250 degrees, remove and leave to cool. Fillet the oranges, cut into cubes. Halve the aubergines, remove the flesh with a spoon, add the garlic and olive oil, finely purée with the mixer, season with salt and pepper and stir in the oranges. Serve the
sea bass fillet with purée and mousseline.