For the duck, preheat the oven to 210C/425F/Gas 7.
Score the skin of the duck breasts in a criss-cross pattern.
Place the duck breasts in an ovenproof frying pan, skin-side down, and cook for 4-5 minutes, or until the fat is rendered. Add the apple to the pan.
When the duck skin is crisp and golden-brown, turn the duck breasts over and cook the other side for 1-2 minutes. Baste the duck with a knob of butter, then roast in the oven for 2-3 minutes (for medium), or until cooked to your liking.
Heat the fennel and coriander seeds in a dry frying pan until aromatic. Grind the seeds in a pestle and mortar. Add the nutmeg, cinnamon and orange zest. Stir in the honey and enough orange juice to give the glaze a good consistency.
Remove the duck breasts from the oven and brush the spice mixture over the duck breasts with a pastry brush. Baste the duck with its roasting juices and leave to rest for a few minutes.
Heat a frying pan until hot, add the duck stock and cook until the volume of liquid has reduced by half, then add the 25g/1oz of butter and whisk until well combined. Season with salt and freshly ground black pepper.
For the creamed Savoy cabbage, heat a lidded frying pan until hot and fry the bacon lardons, carrot and celeriac with the lid on for 4-5 minutes.
Add the cabbage and season, to taste, with salt and freshly ground black pepper.Cover with the lid and continue to cook for 3-4 minutes, or until the cabbage is tender. Add the cream and cook for 1-2 minutes, or until the cream has thickened.
To serve, spoon the cabbage onto serving plates and top with the roasted apples. Slice the duck breasts and place on top.