Cod with Dijon Mustard Sauce

• 55 g butter
• 225 g chopped onions
• 900 g

Melt the butter and sweat the onions in a covered saucepan until golden brown. Skin the cod and cut into portions. Season with salt and freshly ground pepper. Put into a wide saucepan or frying pan, cover with milk and cream, bring to the boil and simmer gently for 4–6 minutes, depending on the thickness of the fish. Remove the fish carefully to a serving dish. Add the flour to the onions, stir