Preheat the oven to 450F. Pat the duck dry with paper towel and place it 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. 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 it will go unflavoured.

Meanwhile, put the apples and plums into a small pot with 2 cups water and bring to a simmer; cook for 20-30 minutes, until the fruit is very soft. Place a colander over a bowl and strain the fruit into it, pressing down on the solids to get as much out as possible. Transfer to a saucepan, add the sugar and bring to a boil. Cook for about 20 minutes, until thickened. Set aside. (You’ll have more glaze than you need; refrigerate about half for a sweet-tart jelly.)

Roast 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). Brush the duck with the glaze, stuff it with the orange and herbs (if you haven’t already), slice the whole crabapples around their middles and add them to the pan if you like, then 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 rest 15 minutes before carving.