Heat the oil in a pan. Sauté the onion and carrots. Pour in the wine and stock, bring to the boil. Reduce the heat, cover and simmer for approx. 20 mins. Blend the soup, season, cover and keep warm.
Remove any bones from the fish fillets with tweezers. Heat the oil in a non-stick frying pan. Drizzle the fish fillets with lemon juice, season, fry for approx. 2 mins. on each side. Arrange the fish fillets on top of the soup, sprinkle with parsley.