1.Preheat oven to 230°C (210°C fan-forced). Squeeze meat from sausage skins. Combine sausage meat, diced apple and lemon thyme.
2.Lay pork belly flat, skin side down, on a work surface. Place sausage mixture along centre of pork, then roll up to form a thick roll. Tie with kitchen string at 3cm intervals to secure. Place in a roasting pan and season skin well with salt.
3.Cook pork for 20 mins. Reduce oven to 210°C (190°C fan-forced) and bake for another 80 minutes, until juices run clear when meat is pierced with a skewer. Remove pork from pan, transfer to a platter, cover loosely with foil and rest in a warm place for 10 mins.
4.To make a sauce, pour off all but 1 tbsp of fat from pan and place on medium heat. Add wine and stir with a wooden spoon, scraping base of pan to dislodge and dissolve any brown bits. Season sauce and strain into a jug.
5.Carve pork into slices. Serve pork, crackling and stuffing with sauce and roasted stuffed apples alongside, if you like.