Put the onion slices at the bottom of the slow cooker. In a small bowl mix together 1 tbsp salt with 1 tsp ground black pepper, the smoked paprika and cinnamon. Put the flour onto a plate then rub the spice mixture over the pork. Heat the oil in a large frying pan and roll the spiced pork in the flour before putting it into the pan to sear it on all sides (you may have to do this in batches). Once the meat is starting to pick up a golden colour pop it on top of the onion slices in the slow cooker.
In a large jug combine all the ingredients for slow cooking the pork then pour over the meat. Pop the lid on and cook on the low setting for 8hrs.
When you’re ready to serve, take the meat out of the slow cooker leaving the cooking liquor behind. Put the cooked meat on a roasting tray or large shallow bowl and pull it into bite-size chunks and shred with 2 forks. Ladle a little of the cooking juices over the pork and mix together.
Toss the fennel and apple slices in the lemon juice and season well then serve along with the pulled pork in bread rolls spread with a little English mustard and mayonnaise if you like.