Season the pieces of chicken and stiffen them in butter without colour. Add 12 button onions and a Bouquet garni containing a piece of fennel. Cover and finish cooking together in the oven.

When cooked, arrange the chicken in a dish and keep warm.

Deglaze the pan with a little mushroom cooking liquor and Rhine wine. Add 2 dl (7 fl oz or ⅞ U.S. cup) cream, 12 very white button mushrooms cooked and cut in slices and a pinch of chopped tarragon and chervil.

Pour the sauce over the chicken and serve.