Preheat oven to 220°C and arrange chicken, bacon, shallots, and herbs in a roasting tin with seasoning.
Drizzle with 2 tablespoons of olive oil and roast for 20 minutes.
Add white wine to the tin and roast for an additional 20 to 25 minutes.
Fry mushrooms and garlic in butter and remaining oil for 5 minutes, then add to the chicken tin with parsley.
Boil chopped potatoes in salted water until tender, then drain.
Mash the potatoes until completely smooth.
Melt butter in milk over medium heat, beat into potatoes, then fold in crème fraîche and salt.
Serve the chicken and sauce on top of a heap of mashed potatoes.