The restaurant opened in 1416 and has five outlets in Beijing. It uses the menlu, or closed-door method, which is the original way of roasting the ducks, although the ovens and cooking fuel are more modern. The birds are roasted in pre-heated gas ovens for about 40 minutes.

To ensure the skin is crisp, boiling water is poured over it, and air is pumped into the carcasses to separate their skin from the layer of fat underneath. The skin is coated with syrup that includes molasses, to give it a rich, brown colour.

Facing stiff competition from smaller, newer specialist restaurants, about three years ago, Bianyifang started serving two new types of roast duck. The Huanxiansu roast duck is cooked with lotus seeds, dates or tea leaves, and served with flower petals, which the diner wraps in the flour pancakes, along with the usual Peking duck accompaniments of sweet sauce, sliced cucumber and spring onions.

For the Shuxiansu roast duck, vegetables are stuffed into the cavity of the bird before roasting to absorb excess oil, and the cooked bird is served with carrot sticks and mint leaves, instead of spring onions, and wrapped in green and orange vegetable pancakes.

'Ladies are looking for healthier diets and businessmen don't want the smell of spring onions on their breath,' says Fang, who claims his restaurant has exclusive rights to make the two new dishes. 'Instead of letting them turn away from traditional Peking duck, we offer alternatives. And the good thing about menlu roasting is [that] the juices don't evaporate and the meat will be more juicy and tender.'

The newly opened Jingcai Roasted Duck has joined the trend of offering less-fatty dishes, and the food is served in modern, western settings, with regular Peking opera performances, mainly for tourists.

'We changed from traditional Chinese decor to a trendy, comfortable and western style because we believe this can attract young people and foreigners,' says Jingcai's owner and manager, Yan Zhifei. 'The Olympics will boost the number of visitors to Beijing, but not all foreigners want to eat in places with dingy decor and dirty floors.'

Using the open-door roasting method known as gualu, which is the most popular way of cooking the ducks in Beijing, Jingcai has a specially designed open, brick fireplace. The bird is roasted over a wood fire for three hours, which allows more fat to melt from it. Date and apple wood are the favoured fuel.

'Using this cooking method, the skin is crackling crisp and subtly flavoured with the taste of dates and apples,' Yan says. 'Good Peking ducks should have succulent meat, date-red, crispy skin and a fruity aroma. It shouldn't be too hard or dry, and must be served when it's still hot.'

When carving the duck in front of the diners, Jingcai's chefs remove the fat from under the skin and presents some of the duck with the skin or meat alone, and some with it served together.

Although the skin is usually the highlight of the dish, Yan says some diners avoid it, thinking it too fatty. 'Health- conscious people don't like eating the skin, and that's why we present it separately from the meat,' he says.

But there are still places where you can get more traditional Peking duck in a Chinese environment. The Liqun Roast Duck Restaurant is a ramshackle courtyard home surrounded by dark alleys, and often packed with visitors photographing the chef as he roasts the birds.

Although the environment is far from comfortable, and there's a faint smell of wood smoke from the open-brick fireplace near the entrance, there's a long queue for tables every night. The restaurant has drawn famous guests such as former US vice-president Al Gore and martial arts star Jet Li Lianjie.

In 1992, chef Zhang Liqun began the roast duck restaurant in the courtyard home his family had owned for over a century. He says the traditional setting stimulates diners' appetites and piques their sense of culture. 'It's more than just Peking duck, it's a place with culture and history,' Zhang says. 'It's a typical house of Beijingers. After all, Peking duck is a traditional dish and people like the way it used to be. It deserves a traditional environment too.'