Preheat the oven to 200C/400F/Gas 6.
For the pork belly, boil a kettle and pour the boiling water over the pork skin, discarding the water.
Pat the pork belly dry, using kitchen paper, then rub the salt over the skin, pressing them into the score marks.
Place the cinnamon sticks, cloves, sliced apples, oranges and cider into the bottom of a roasting tin. Place the pork belly on top and roast for one hour in the middle of the oven. Then, reduce the temperature to 140C/275F/Gas 1 and cook for 2 hours. Add more cider to the bottom of the roasting tin if all the liquid evaporates.
Once cooked, remove the pork belly from the oven and set aside to rest for 15 minutes.
Meanwhile, for the mulled cider cabbage, melt the butter in a lidded pan over a medium heat and fry the onion for 4-5 minutes, or until softened. Add the cinnamon stick, nutmeg, star anise and bay leaf and continue to cook for another 1-2 minutes. Stir in the cabbage, cider and sugar until well combined and the sugar has dissolved. Season, to taste, with salt and freshly ground black pepper.
Bring the mixture to the boil and reduce the heat until the mixture is simmering. Cover the pan with a lid and simmer over a low heat, stirring occasionally, for 1-1½ hours, or until the cabbage is tender and the liquid has evaporated. Remove the star anise and cinnamon stick and stir in the redcurrant jelly.
For the salted almonds, mix the almonds and oil in a bowl and season, to taste, with salt and freshly ground black pepper. Transfer to a baking tray and roast in the oven for 10 minutes, or until golden-brown. Remove from the oven and set aside to cool.
To serve, carve the pork belly into squares. Spoon some mulled cider cabbage into the centre of each of 8 serving plates, top with a piece of pork belly and spoon over some cooking juices. Garnish with the roast almonds.
