Preheat the oven to 130°C fan (150°C conventional).
Cut the pork belly into thick pieces, about 8–10cm long. Rub them all over with plenty of salt and pepper, then arrange them snugly in a large, deep-sided roasting tray in a single layer. Tuck in the garlic, thyme and bay leaves, spoon over the rendered pork fat and pour in the water.
Cover the tray tightly with foil, sealing the edges well, then cook for 3–4 hours, or until the pork is meltingly tender.
Traditionally, the pork for rillettes is shredded along the grain using two forks, creating long, tender strands. It's a technique that works beautifully. If I'm making a larger batch, though, I sometimes use the end of a wooden rolling pin to gently bash the pork instead. It's much quicker, although the purists might not approve.
Transfer the shredded pork and all the rendered fat to a large bowl, discarding any membrane, cartilage or bone.
Strain the cooking juices through a fine sieve into a clean jug. You should have about 500ml of cooking liquor. Stir it well, then ladle enough over the pork to moisten it generously, mixing everything together well. Any remaining cooking liquor can be chilled. Once cold, the fat will set on top of the stock, allowing you to separate them and use both in other recipes.
Taste and adjust the seasoning with salt and pepper, then pack the rillettes into sterilised jars, ramekins or simply spoon into a serving bowl.
Cover and chill until set. The rillettes will keep in the fridge for up to 10 days.
