For the pork belly, place the pork belly, chillies, lemongrass, garlic, coriander, ginger and lime leaves into a large saucepan. Top with water, so the pork is covered, then bring to a boil. Reduce the heat to a simmer and cook for two hours.
For the pickled vegetables, place the turnip and cucumber in a heatproof bowl. Put 110ml/4fl oz water in a pan with the white wine vinegar, sugar and salt, and heat until the salt and sugar have dissolved. Pour over the turnip and cucumber and set aside to pickle for two hours, then drain off the pickling liquid.
For the pork belly, when poached, remove from the heat and place between two heavy baking trays and place in the fridge for at least two hours to cool and set.
For the chilli jam, heat the sugar in a heavy-based saucepan over a low to medium heat until it melts and forms a golden-brown caramel. Do not stir and keep an eye on it so that it doesn’t burn.
Blend all of the remaining chilli jam ingredients, except the crème fraîche, in a food processor to a smooth purée.
Once the sugar has caramelised, pour in the puréed chilli jam mixture and stir well. Bring the mixture to the boil, then reduce the heat and simmer for 4-5 minutes, or until sticky and jam-like. Remove from the heat and set aside to cool slightly.
For the pork belly, remove the pork from the fridge and cut into 1cm/½in thick slices. Heat a frying pan until hot, add a splash of oil and a knob of butter, and fry the pork slices on each side for 1-2 minutes, or until golden-brown and crisp.
Add a couple of spoons of the chilli jam to the pan and continue to fry, basting as you go until coated and slightly sticky.
To serve, lay three slices of the pork belly on to the plate, dress with the pickled vegetables, watercress, coriander and mint leaves and finish with a few dots of chilli jam.