


Clean and peel the vegetables. Stick one clove in each onion. Put the stick of fresh tarragon into boiling water for 10 seconds, strain it and put it inside the boiling fowl, add salt, pepper and the giblets. Tie up the boiling fowl.
Put the boiling fowl inside a big saucepan, fill it with cold water to cover the boiling fowl. Cook gently until it boils, add salt and pepper. Skim and add vegetables and the bouquet garni.
Let it boil again and reduce the heat until the water gently comes to the boil. Cover the saucepan and cook for 3 hours.
Melt the butter in a saucepan, add the flour, mix and cook for 2mn while stirring.
As soon as the mixture starts browning, gently pour 50cl of stock still stirring. Let it thicken at a medium heat. Blend the cream and the egg yolk together in a bowl, add salt, pepper and a little bit of stock. Mix with the white sauce.
Strain the boiling fowl and cut it into pieces, serve in a hot dish and top it with the sauce.