Preheat the oven to 190°C/fan 170°C/gas mark 5. Pop the mushrooms into a small bowl and cover with boiling water. Bash the fennel and coriander seeds, paprika and seasoning in a pestle and mortar. Carefully cut the squash in half lengthways, deseed, then chop into 4cm chunks. Toss with half the spice mixture and 1 tsp olive oil on a baking tray. Roast for 50 minutes, or until golden, then remove from the oven and reduce the temperature to 150°C/fan 130°C/gas mark 2.
Meanwhile, drizzle both cuts of meat with the remaining olive oil and rub with the remaining spice mixture, then place a large casserole pan on a medium-high heat. Place the pork and the brisket in the pan fat-side down and brown on all sides for around 15 minutes in total, then peel and roughly chop the onions. Remove both meats to a plate, reduce the heat to medium, add the onions and sugar to the fat and fry for 10 minutes, stirring regularly until lightly caramelised. Add the balsamic vinegar and most of the mushroom liquid, discarding any gritty bits. Roughly chop and add the mushrooms, followed by the beans, liquid and all, and the tomatoes, breaking them up with a spoon, then return both meats to the pan. Loosen with a splash of water if needed, then bring to the boil, season and pop a layer of damp greaseproof paper directly on the surface. Cover with tin foil and cook in the oven for around 5 hours, or until the meat is tender.
Prick the peppers and chillies, then blacken all over on a barbecue or in a griddle pan. Place in a bowl, cover with clingfilm and leave to cool, then peel and deseed them, keeping as much juice as you can for extra flavour. Roughly chop with half the coriander, and toss with a little seasoning. When the meat is tender, remove from the oven, break up the meat, then stir in the squash, peppers and chillies. Adjust the consistency with water if needed, taste and season to perfection, then keep warm.
To finish, peel the onion, then finely chop with the apples and the remaining coriander. Dress with the cider vinegar and extra virgin olive oil and season. Serve the chilli with the salsa, bread or rice and a dollop of yogurt.