4 apples, cored and cut into wedges
1 large head cavolo nero, leaves removed and stalks discarded
3 fennel bulbs, sliced horizontally into quarters
6 garlic cloves, crushed
2 lemons, zest only
3 onions, sliced horizontally into quarters
2 sprigs fresh thyme
1 bay leaf
salt and freshly ground black pepper
20g/½oz golden caster sugar
3 tbsp fennel seeds
2 tbsp olive oil
1 tbsp cider vinegar
40g/1½ oz unsalted butter
1 small rack free-range pork loin, bone in, skin on and scored