These can be served in many different manners, with sauce béarnaise, sauce crevette, sauce au vin blanc, etc. The best way to prepare the fillets is always the same, as follows: fillet the fish and roll each fillet. Put in a dish the bones and the skin, some butter, two onions, a little white wine, salt and pepper; begin cooking over the fire, finish in the oven, basting frequently. You can, if you like, stuff the fillets with a mixture of a little white fish and mushrooms chopped together. You can also serve these fillets simply with the sauce in which they have been cooked passed through a sieve.