Heat the olive oil in a pan, add the chopped onions, sprinkle with wine and boil. Remove from the heat and add a half tsp of flour, return the pan to the heat and cook until the sauce is thick. Add a tsp of curry powder, add the cream and salt.  Put salt and pepper on the fish fillets, put them in an oven dish, cover with the curry sauce, cover the dish with foil and put in the oven at 200ºC for about 20 minutes. Serve the fish with its sauce.