Haddock with lemon sauce

• 1½ lb (700 g) fresh haddock fillets
• ½ small onion

Skin and cut the haddock fillet in 4 pieces. Peel and finely chop the onion. Grease a baking dish and sprinkle with the onion. Arrange haddock pieces in the dish, season with salt and pepper and pour over the wine. Cover with a buttered paper and cook in an oven heated to 350°F (180°C) or gas no. 4 f