Cut the pork into small pieces. Peel and core the apples and cut them into slices. Arrange the pork and layers in a pie dish in layers, seasoning well with salt and pepper, nutmeg and sugar. Pour in the cider and top with the butter. Cover with pastry and bake at 400°F, 200°C, gas mark 6 for fifteen minutes. Reduce the heat to 375°F, 190°C, gas mark 5 and cook for forty-five minutes.