1Preheat the oven to 450F. Pat the duck dry with paper towel and place in a roasting pan. Poke through the skin-without going into the meat-with a bamboo skewer or the tip of a knife in several places. (Do this by pulling up on the skin and poking it through as if you were threading fabric - these holes allow the excess fat under a duck's skin to render off in the oven.) Drizzle with oil and sprinkle with salt and pepper. If you like, tuck the orange and herbs into the cavity – otherwise wait for halfway through the roasting time, after you’ve poured off some of the fat for later use - this way the fat will remain unflavoured.
3Roast the duck for 30 minutes, then remove the duck from the oven and pour most of the fat from the pan into a jar (store in the fridge for up to a month). Stuff the orange and herbs into the cavity, add diced potatoes and 1-inch chunks of carrot to the pan if you like, reduce the heat to 350F and return to the oven to roast for 1 1/2-2 hours, until the legs wiggle in their sockets and a meat thermometer reads at least 175F. Let the duck rest 15 minutes before carving. Serves 4.