Duck benefits from slow roasting. The more tender the leg meat, the better; and the breast meat can withstand longer cooking than can that of turkey or chicken thanks to lubrication from its surrounding fat. Another reason why I prefer to give a duck longer in the oven is that I have found that conventional timings -- usually those also recommended for chicken -- are rarely sufficient.
Gary Rhodes, in New British Classics, has a recipe for slowly roasted duck with honey. You smear your duck with 5 tbsp honey, and roast it at gas mark 3/160 C. That is too much honey, in my opinion; and an unnecessarily high oven temperature.
I had a 2.8 kg duck. I was not confident that I could cook it successfully if I used only the lowest oven setting; but my experience with chicken suggested that the setting would work provided that there was an initial blast of heat. I took the duck out of the fridge three hours early. I made little incisions in the skin with the sharp point of a knife (I wonder if this is necessary -- the fat would probably run freely anyway), rubbed in some salt (a daughter would have objected if I had used pepper as well), and stuffed the bird with a lemon and a star anise.
I put the duck into the middle of an oven pre-heated to gas mark 6/200 C, for half an hour. Then I took it out of the oven, and spread over it 1 tbsp honey -- which might have burned at the high temperature. I returned the duck to the oven, now at its lowest setting, marked with an "S".
This setting, in my oven, is not very low. My oven thermometer -- which I must assume is roughly accurate -- rose to 130 C, which is not far off the official temperature of gas mark 1.
I cooked the duck for a further three hours, basting it regularly. Half way through cooking, and again near the end, I drained the juices into a glass bowl, allowed them to settle, and spooned off the fat. You cannot perform this process with total accuracy; after I had reduced the fat to a thin layer on top of the juices, I blotted off as much of the rest as I could with pieces of paper towel.
I made a stock with the duck giblets; but the juices from the roasting tin provided enough sauce.
When I took the duck out of the oven, I moved the shelf on which it had been sitting to a higher position, turned up the dial to gas mark 8/230 C, and put in another roasting pan with a layer of duck fat. After five minutes, I tipped in some parboiled cubes of potato, which roasted -- with one turning -- in 30 minutes, while the duck was resting.
The skin of the duck was a lovely, golden brown -- although not, I must admit, crisp. The sauce, with its honey and lemon and star anise, had just the right sweetness and acidity and savouriness to offset the richness of the meat.