Roast Pork Loin with Fennel and Apples

Pat the pork dry. Score the fat cap in a shallow crosshatch about 2 cm apart, cutting through the fat but not into the meat. Mix 13 g of the salt with the fennel seed, pepper, garlic, rosemary, and 15 ml of the olive oil into a paste and rub it all over, working it into the scores. Rest uncovered at room temperature 45 minutes to 1 hour (or refrigerate up to 24 hours, then give it 45 minutes out of the fridge). If the roast is untied, tie it with kitchen twine every 4 cm to keep an even cylinder.

Heat the oven to 400°F (200°C). Heat 15 ml of oil in a large ovenproof skillet or flameproof roasting pan over medium-high heat. Sear the pork fat-side down first for 4–5 minutes, until the fat is golden and rendering, then brown the other sides 2 minutes each. Remove to a plate.

Toss the fennel, apples, and onion with the remaining 15 ml oil and the remaining 3 g salt, and spread in the pan (or a 23 × 33 cm / 9 × 13 in roasting pan). Set the pork fat-side up on top. Roast 50–70 minutes until an instant-read thermometer in the center of the roast reads 145°F (63°C). Start checking at 45 minutes. Move the pork to a board, tent loosely with foil, and rest 15 minutes — the temperature will rise a few degrees and the juices settle.

Move the vegetables and apples to a platter. Set the roasting pan over medium-high heat, pour in the cider, and scrape up the browned bits. Boil 4–6 minutes until reduced by about half. Whisk in the mustard, then take off the heat and swirl in the cold butter until glossy. Add any resting juices from the board. Slice the pork 1 cm thick and serve over the fruit with the sauce spooned on top.