Preheat the oven to 180'C. Season the chicken.
Heat the oil in a frying pan and then add the chicken to the pan, skin side down, and cook until golden brown. Turn the chicken over and add the butter and thyme to the pan. Use the melted butter to baste the chicken and then trasnfer to a baking sheet and cook in the oven for 12 to 15 minutes. Reserve the pan and the cooking juices and use to cook the vegetables.
Peel and finely dice the shallot and the garlic. Peel and dice the carrot. Cut the celery into slices. Pick and finely chop the parsley leaves.
Add the vegeables to the pan used to cook the chicken. Season and cook until the vegetables begin to soften. Add the flageolet beans to the pan, pour in the wine and cook for 5 minutes. Add the stock to the pan and allow to reduce down. Fold in the parsley and a knob of butter.
Brush the girolles clean and tear into smaller pieces. Heat the butter in a pan, add the girolles and cook over a high heat until golden brown. Season well.
Carve the chicken supremes on the angle. Place a neat pile of the flageolet beans in the centre of the plate and arrange the chicken on top. Garnish with the girolle mushrooms and freshly picked chervil.
«Avoid washing mushrooms in water as they will soak it up. Instead, use a small brush to remove any dirt. »