French trimmed roast pork

Name: French trimmed roast pork
Ingredients: 3kg/10½oz French trimmed rack of pork; olive oil, for rubbing; salt, to season; 1 tbsp olive oil; 1 onion, finely chopped; 50g/1¾oz cranberries or roughly chopped prunes; 5 tbsp calvados or brandy; 2 large sprigs thyme, leaves picked; ½ tsp ground allspice; nutmeg, to grate; 500g/1lb 2oz sausagemeat; 100g/3½oz cooked chestnuts, crumbled; 1 onion, sliced; few sprigs thyme; 3–4 tart eating apples, halved horizontally; 1 tsp soft light brown sugar; 1 tbsp flour; 200ml/7fl oz cider; 400ml/14fl oz chicken or pork stock; 1 tsp apple jelly (optional); ½–1 tbsp calvados or brandy (optional)