A cast-iron casserole dish is ideal for this recipe. Alternatively, use a heavy frying-pan, transferring to a casserole dish at the appropriate time.
START by making the stock. drop about 2 tablespoons of olive oil into a large, heavy pan fry the roughly chopped chicken carcass and the stock vegetables until they take on a good colour.
Once everything is golden brown, pour on about 1 litre/2pints of water and bring to the boil. Simmer for 30 40 minutes, then strain and discard the solids. Reduce the stock by rapid boiling to give 250 ml/1/2 pint. Allow to cool.
Cut the chicken into eight pieces and arrange in a shallow dish. Prepare the marinade vegetables. Mix the cooled wine and stock together, add the marinade vegetables and pour over the chicken. Cover and leave overnight.
The following day lift the chicken pieces from the marinade and pat dry.
Cut the bacon into lardons. In a heavy lidded casserole dish, melt the butter with 2 tablespoons of oil and cook half the lardons until the fat runs.
Fry the chicken pieces, a few at a time, until they are golden brown on all sides. Take your time as this frying gives the dish a more intense flavour.
When all the chicken is browned, return all the pieces to the casserole dish. Pour the marinade and vegetables over it and bring everything to the boil. Cover with a tight fitting lid.
Either simmer over a low heat for 90 minutes or place the covered dish in a preheated oven 160C/325F/gas mark 3 for the same length of time.
Meanwhile, peel the tiny onions, and cook the remaining lardons in a heavy frying pan until the fat runs, then add the onions and cook until they begin to colour.
Wipe the mushrooms.
Once the chicken is tender, remove the pieces form the sauce and keep warm. Strain the sauce, pressing hard on the vegetables. Now wipe out the dish and pour back the strained marinade, then add the lardons, onions, and mushrooms. Simmer for 5 minutes.
Using a palate knife, knead together the butter and flour until you have a smooth paste.
Drop pieces of this into the sauce, whisking gently until the sauce thickens. Taste and correct the seasoning. Replace the chicken and simmer for 3 to 4 minutes. Cut the bread into croutons and fry in olive oil until golden. Rub with garlic and sprinkle with chopped parsley.
Serve the chicken with croutons and creamy mashed potatoes.