- Preheat the oven to 75 °C (150 °F).
- With a sharp knife, score the skin of the duck breasts in a large crosshatch pattern, exposing the fat but not cutting into the meat. In a skillet, brown the breasts skin side down for about 10 minutes. Turn over the breasts and brown the other side. Season with salt and pepper.
- Place the duck in a baking dish and keep warm.
- Remove the fat from the pan. In the same pan, without cleaning it, soften the shallots while stirring.
- Deglaze with the cider and reduce by half. Add the remaining ingredients and simmer gently for 5 minutes. Remove the rosemary sprig when the flavour is sufficient. Adjust the seasoning.
- Cut each breast into thin strips again the grain of the meat, that is to say, into thin slices. Drizzle with the peach sauce.