Preheat the oven to 180°C conventional oven/ 160°C fan-forced (350° Fahrenheit/Gas 4).
Use a sharp knife to lightly score the skins of the duck breasts. Season the duck breasts well with salt and pepper.
Place the duck breasts, skin side down, in a large, heavy-based frying pan (cold). Heat the frying pan to medium-high heat. Cook until most of the fat has rendered and the skin is golden brown (approximately 5 minutes).
Turn the duck breasts over. Pour the duck juices from the frying pan into a small saucepan. This will add lovely flavour to the balsamico (balsamic) sauce. If your frying pan is oven proof, transfer the frying pan to the oven. Alternatively, transfer the duck breasts to a baking dish, skin side up. Bake for 7-10 minutes for medium or until cooked to your liking. Remove the duck breasts from the oven and allow to rest.
Meanwhile to make the balsamico sauce, add the garlic, rosemary, balsamic vinegar, vegetable stock and honey to the saucepan with duck juices. Cook until the sauce has reduced and thickened to your required consistency.
To serve, slice the duck breasts diagonally. Spoon the hot balsamico sauce over the duck and serve with sweet potato mash – buon appetito.