Trim the chicken pieces and season with salt and pepper. Melt the butter in a frying pan over moderate heat. When hot and foaming, add the chicken pieces and fry for 10 minutes, turning occasionally, until brown all over. Lower the heat, cover with a pan lid, and cook gently for 30 minutes until tender. Trim and slice the mushrooms.
Add the brandy to the frying pan and set alight shake pan gently so flames spread over the contents of the pan. Flaming burns off excess fat and greatly adds to the flavour of the dish. When flames go out, add the mushrooms, tomato puree and white wine. Boil the sauce, stirring occasionally, for at least 5 minutes to reduce and concentrate the flavour. Add the prepared brown sauce and heat through. Check seasoning and spoon chicken pieces and sauce on to a hot serving platter. Sprinkle with chopped parsley and serve.