Preheat the oven to 180°C. Remove excess fat from the neck and bottom cavity of the chicken, then remove wing tips by chopping through the outermost joint with a sharp knife. Using your fingers, loosen the skin around the breast and thighs, then massage some of the Simon Gault Italian seasoning under the skin. Liberally season the cavities too, as well as the inside and outside of the chicken. Place chicken, breast side up, on a roasting tray and cook in the oven for about 1 hour 15 – the internal temperature should reach 65°C or the juices should run clear when the thickest part of the thigh is pierced with a skewer. Allow chicken to rest for a good 10 minutes in a warm place. Peel and roughly chop potatoes. Place in a saucepan, cover with cold salted water and bring to the boil. Simmer until just past tender. Drain and pass through a potato ricer, or mash. Add butter to the hot milk and cream. Return mashed potato to the heat and add milk, cream and butter, stirring until the mixture is smooth and creamy – not all the liquid may be needed, depending on how starchy the potatoes are. Add nutmeg and chopped herbs and season to taste with salt and pepper. If you decide on the luxury of truffle oil, add it just before serving, with a final whisk. To make sauce, heat a saucepan and pour in the Madeira, bring to the boil and reduce by half. In a bowl, mix water with Gault's Beef Stock and cornflour. Pour mixture into the pan and stir while bringing back to the boil, then whisk butter in, remove from the heat and finish with cracked pepper. Set aside. For the slaw, mix mayonnaise with minced garlic and set aside. Remove the dry outer leaves of both cabbage halves and discard. Cut cabbage in half again, then slice thinly. Place in a large mixing bowl with peanuts, parsley and balsamic vinegar. Add enough of the mayonnaise to coat the slaw, and season with salt and pepper to taste. Mix well. To assemble, place cooked chicken on a chopping board and insert a large chef’s knife into the bird, cutting along the inside of the backbone all the way to the neck. Remove backbone by chopping along either side. Place the resulting chicken halves on the board, skin-side up, and cut diagonally, separating breast and thigh. Transfer chicken pieces to a baking tray and reheat in the oven for 5 minutes. Heat mash in a saucepan or the microwave and spoon onto warmed plates. Stack a breast or a leg on each serving of mash. Arrange the slaw on the plate, next to the mash. Bring the Madeira sauce to the boil, and then pour over and around the chicken and mash. Serve and enjoy.