Preheat the oven to 190C/375F/Gas 5.
For the stuffing, heat the butter in a frying pan and add the onion. Cook the onion in the butter until softened.
Once the onion is soft, remove from the pan and add the breadcrumbs, dried fruit and the thyme leaves. Season with salt and freshly ground black pepper.
Add the egg to the mixture, binding it together. Stuff the pig's trotter with the mixture and tie it together with butchers' string.
For the pig's trotter, arrange the carrots, onions and thyme leaves in a lidded ovenproof dish. Place the trotter on top of the halved carrots and onions.
Pour over the stock and cook in the preheated oven for 2-3 hours. If the dish looks like it's going too brown, cover with the lid and continue cooking. Serve hot.