For the marinade, clean, wash and chop the soup vegetables. Peel and halve the onions. Wash the thyme. Mix with wine, onions, soup greens, bay leaf and peppercorns.
Wash the chicken and pat dry. Separate legs and wings from the fuselage. Cut off chicken breasts on the bone along the sternum and cut in half crosswise.
Put the freezer bag in a bowl and put chicken pieces in it. Add the marinade and close the bag well. Keep in a cool place for at least 1 day. Turn from time to time.
Peel, wash and chop the carrots. Clean the mushrooms, wash and halve them if necessary. Peel shallots and garlic, dice both. Preheat the oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3).
Remove the chicken and pat dry. Keep the marinade and sieve. Heat the oil in a frying pan. Brown the chicken parts all around. Add shallots, mushrooms and carrots and fry briefly.
Season everything with salt and pepper. Dust with flour and sauté briefly while turning. Add marinade, bring to the boil. Cover and braise in the oven for 1-1 1/4 hours. Season to taste with salt, pepper and sugar.