Put the boned chicken on a large chopping board with the breast skin downwards, neaten up the edges with a knife and open out flat.
Slit the sausages lengthways, peel off the skins and put the meat into a large bowl. Add the onions, red pepper, sun-dried tomatoes, olives, basil, breadcrumbs, egg yolk and plenty of seasoning and mix with a wooden spoon. Spoon on to the centre of the chicken. Fold the legs, wings and remaining skin back into position so that the stuffing is enclosed. Tie with string like the spokes of a wheel, adjusting the string and patting into shape to form a round cushion.
Weigh the joint, then put it breast side up in a roasting tin. Drizzle with the oil and season lightly. Cover with foil and roast in a preheated oven, 190°C (375°F), Gas Mark 5, for 20 minutes per 500 g (1 lb) plus 20 minutes. Remove the foil for the last 30 minutes and baste the chicken once or twice with pan juices until a deep golden brown and cooked when tested (see
Allow to cool, remove the string and cut into wedge shapes. Serve with salad.