Roast pork with crackling, celeriac and apple sauce

For the spice rub, toast the spices in a dry frying pan for 2-3 minutes, until fragrant. Crush in a pestle and mortar with 10g flaky sea salt to a mostly fine powder, then mix through the remaining 15g salt. Pat the pork dry with kitchen paper. Remove the string and set aside, then use a sharp knife to define the scores in the skin. Rub the spice rub generously all over the pork. Put on a tray, uncovered, for 30 minutes.

Preheat the oven to 180˚C, gas mark 4. Cut the onions into wedges then scatter in a deep roasting tin with the garlic, sage, celeriac and bay leaves; nestle the apples in the centre. Wipe the spice rub off the pork, pat dry and put on top of the veg. Roast for 1 hour 30 minutes until piping hot in the centre (65-70˚C on a meat thermometer).

Transfer the pork to a board. Using a sharp knife, carefully remove the skin and put it on a baking sheet with the roasted celeriac. Cover the pork with foil; rest for at least 30 minutes. Turn the oven up to 220˚C, gas mark 7. Roast the skin and celeriac for 10-15 minutes, until the skin crackles and puffs up and the celeriac has browned evenly. Meanwhile, use a fork to mash the roasted apples in a bowl; keep warm.

For the gravy, discard the sage, garlic and bay leaves from the onion tin, then put the tin on the hob (or transfer the contents to a pan) over a high heat. Tip in the flour and cook, whisking, for 3-4 minutes, until just starting to catch. Add the calvados (or brandy) and boil rapidly, scraping the base of the pan, until thickened again. Add the stock and bubble, whisking, for 4-5 minutes. Stir in any meat resting juices and simmer briskly for 4-5 minutes until thickened; season and keep warm. Carve the pork and crackling into thick slices; serve with the celeriac, gravy and apple sauce.