Boil water, sugar, salt, rosemary, and garlic, then cool completely.
Brine the pork neck in the cold liquid for 10 hours.
Preheat your oven to 150°C.
Wash the pork in cold water and place it in a casserole dish.
Cover the meat with 2 litres of rapeseed oil and bake for four hours.
Cool the pork, wrap tightly in cling film, and chill in the fridge.
Boil potatoes in salted water, drain, and lightly crush with butter.
Mix carrots, celeriac, and mayonnaise to create the coleslaw.
Blend herbs, mustard, vinegar, oil, garlic, and pepper for the dressing.
Slice the chilled pork into 2cm pieces and fry until golden-brown.
Serve the pork over potatoes with coleslaw and dressed mustard leaves.