For the bread sauce, heat together the first eight ingredients until just bubbling for two minutes. Put on the lid, turn off the heat and set aside to infuse for half an hour. Strain the milk through a fine sieve into a clean pan, pressing down with a spoon to extract all the liquid.
Add the cream to the milk mixture and gently heat. Whisk in the breadcrumbs. Leave for a few moments to allow the crumbs to swell. Season to taste with more salt and then pour the sauce into a bowl. Cover with a plate and keep warm over a pan of hot, but not boiling water, until needed.
Preheat the oven to 200C/400F/Gas 6.
Rub half of the oil over the chicken and sprinkle with plenty of salt, set aside. Heat the remaining tablespoon of oil in a roomy casserole dish and lightly brown the chopped chicken wings and giblets over a medium heat. Place the prepared chicken on top, sitting it between the wings and giblets. Add pepper and the vermouth. Roast for ten minutes.
Decrease the oven temperature to 180/350F/Gas 4 and cook the chicken for a further 45 minutes to an hour and 20 minutes, depending on the weight of the chicken. Check the chicken is cooked by inserting a skewer into the thickest part of the meat – if the juices run clear, the bird is cooked.
Meanwhile remove the skins from the sausages and wrap in the bacon. Place into a small roasting dish and cook alongside the chicken for about 20-25 minutes, or until they are sizzling and nicely browned. Keep warm.
Remove the chicken from the oven. Transfer it to a roasting pan, first letting the juices drip back into the casserole dish it was cooked in. Cover the chicken with foil and leave it somewhere warm for up to 30 minutes to rest.
Add the chicken stock to the roasting pan and place over a medium heat, cooking until the liquid becomes a rich, syrupy gravy. Strain into the casserole dish.
Add the cooked potatoes to the casserole dish and turn them in the juices over a medium heat on top of the stove. Place back into the oven until ready to serve.
Carve the chicken onto a warmed serving dish, surround with the potatoes and sausage and bacon rolls. Serve the gravy juices and bread sauce at the table, in sauceboats or small jugs.
Roast for 20 minutes per lb (450 g) plus approx 10-20 minutes extra until juices run clear when the bird is pierced in the thigh with a skewer.