Pork shoulder is a fatty cut that's perfect for slow roasting because it stays wonderfully moist even after 6 hours in the oven.
Preheat the oven to 170C/150C Fan/Gas 3.
For the pork, using a sharp knife, score the skin of the pork in strips. Rub the skin all over with olive oil then rub in the salt, thyme and lemon zest. Place the onions in a deep-sided roasting tin, put the pork on top and roast for 5 hours.
For the apple sauce, put the apples in a saucepan with 3 tablespoons water, the butter and 2 tablespoons sugar. Cover and place over a medium heat until soft and fluffy, stirring occasionally. Taste and add more sugar if desired. Set aside.
For the pork, after 5 hours, increase the oven temperature to 230C/210C Fan/Gas 8 and roast the pork for a further 40-45 minutes, or until the crackling is crisp.
For the mash, cook the potatoes in a saucepan of boiling salted water for 10-15 minutes, or until tender.
Drain the potatoes, then return to the pan to the heat and gently warm to remove any excess moisture. Remove from the heat and mash the potatoes with the butter and cream until smooth. Season, to taste, with salt and freshly ground black pepper. Set aside and keep warm until ready to serve.
For the spring greens, heat a frying pan until hot, add the butter and, when melted, add the cabbage and a splash of water. Cook for a few minutes, or until the cabbage is tender and most of the water evaporated. Season with salt and black pepper.
To serve, carve the pork into thick slices and place on plates. Spoon the potatoes alongside with a large dollop of apple sauce and the cabbage. Drizzle over the gravy.
