Preheat the oven to 230°C.
Roast chicken legs and wings in a deep tray for 20 minutes.
Reduce the oven temperature to 180°C.
Mix softened butter with half the truffle, salt, and pepper.
Push the truffle butter underneath the skin of the chicken crown.
Roast the chicken for 1.5 hours, adding carrot batons for the final 30 minutes.
Sauté onions, chopped carrots, leeks, bay leaves, and thyme in oil for 4 minutes.
Add roasted legs and wings to the pan with 2 litres of water and simmer for 1 hour.
Strain the stock and reserve 500ml of liquid.
Sauté shallots and garlic in melted butter for 2 minutes.
Reduce white wine by half, add stock, reduce again, and stir in cream and chervil.
Sauté kale and peas in butter until the kale wilts.
Serve sliced chicken over vegetables, topped with sauce and remaining truffle.