Take the pork out of the fridge at least 1 hour before cooking to allow it to come to room temperature.
Preheat the oven to 220 degrees Celsius.
Toast the caraway and fennel seeds in a small frying pan until fragrant and starting to pop.
Pat the pork skin really dry with lots of paper towel (moisture affects the crispiness of the crackling). Drizzle half the oil onto the skin and season with a generous amount of salt. Turn the pork over and rub the spices over the flesh.
Place the vegetables, garlic, bay leaves and thyme in the centre of a large, deep roasting tin, drizzle on the rest of the oil and season with a pinch of salt and pepper. Place the pork, skin-side up, on top and tuck most of the vegetables underneath.
Roast in the oven for 20-30 minutes, or until the skin is blistered, golden and crunchy. Remove from the oven.
Reduce the oven temperature to 165 degrees Celsius.
Place the pork on a chopping board. Put the tin over medium heat on the stovetop and cook until the vegetables start to sizzle and colour a little more. Pour in the cider, bring to the boil and cook for 4-5 minutes.
Return the pork, skin-side up, to the tin. Pour the stock around the pork, ensuring it does not touch the skin. The aim is to have enough liquid to cover most of the flesh. If you need a little more liquid, adding water is fine.
Return to the oven for 4 hours. Add the apples to the liquid in the tin and cook for another 25 minutes or so until the pork pulls apart easily with tongs.
Remove from the oven and carefully transfer the pork and apples to a chopping board. Discard the thyme and bay leaves, leaving the vegetables in the liquid. Place the tin over high heat on the stovetop and bring to the boil.
Cook until reduced by half, skimming off the excess fat with a ladle.
Remove the crackling from the pork and scrape off the soft fat from the underside. Break the crackling into shards. Pull the meat apart and place on a large platter with the crackling and apples. Pour the pork jus and soft vegetables into a bowl and serve on the side. Serve with a potato gratin or roasted potatoes and steamed greens or a green salad with a mustardy dressing.
Place the pork in the roasting tin on the oven rack and then fill the tin with stock, as this helps to avoid spills while transferring.