Photograph: Jonathan Gregson
Pat the pork belly dry with kitchen paper and place on a plate, skin-side up. Chill the meat in the fridge, uncovered, overnight. Tip the sour cherries for the chutney into a bowl, add the apple juice to cover and soak overnight.
The following day, crush the star anise and the fennel seeds using a pestle and mortar, then grind them, together with the paprika and the bay leaves, in a coffee grinder or blender. Tip the herbs and spices into a bowl and mix in the sea salt. Rub the mixture all over the pieces of pork belly.
Preheat the oven to 190°C, fan 170°C, gas 5. Put all the chutney ingredients (including the soaked cherries and any juice) in a roasting tin, mix together and cover with kitchen foil. Bake for 1 hour, stirring the mixture once or twice. Remove the foil and continue to bake for another 20-30 minutes, stirring halfway through. The chutney should be glossy, slightly caramelised and with a nice syrupy consistency. Remove from the oven and leave to cool.
To roast the pork belly, reduce the oven heat to 160°C, fan 140°C, gas 3. Place the belly, flesh-side down, in a shallow roasting tin lined with baking parchment. Add 200ml water and roast for 2-2½ hours. Timing will depend on the thickness of the belly, but it will take at least 2 hours. You will know it is cooked when a fork pushed into the flesh comes away easily.
When the belly is ready, crank up your oven heat to 220°C, fan 200°C, gas 7 and leave the pork to cook for a further 15-20 minutes. This should make the crackling bubble up and go crispy. A trick we use at the restaurant, when the crackling refuses to behave itself, is to heat up a heavy-based frying pan with a little oil. When it is hot, lay the belly skin-side down and it will puff up like a dream. If the surface of the crackling is uneven, just press it down where it's not touching the pan. Or just place under a hot grill for 5 minutes or so until the crackling bubbles. To carve, turn the pork belly skin-side down and serve with the chutney.
Get ahead: the chutney will keep for a month or so in a sealed container in the fridge.
Kitchen secret: this goes wonderfully with roast sweet potato or shredded cabbage stir-fried with a little chilli and garlic. Any leftover chutney will go perfectly with cheese, roast lamb and chicken, and cold cuts.