This is the time of year when Shanghai experiences its most sweltering temperatures. Bring on the mutton!

According to traditional Chinese medicine, mutton is believed to provide a boost to compensate for the enervation of scorching heat. That same principle applies in winter, when mutton is said to provide "warm" nourishment for the body.

Mutton eating in Minhang dates back at least 200 years. Areas in the district are renowned for cooking goat or sheep mutton. Some have even been listed as a cultural heritage vendors.

Qibao Old Town offers multiple choices for mutton lovers.

Around five in the morning, the old commercial streets in the town are filled with noise of the mutton restaurants opening up and residents coming in to order the dishes or get takeaways.

Freshly cooked mutton chunks are placed with the skin on the top, waiting to be sliced and cooked to order. The mutton has been stewed overnight, rendering it very tender.

For those dining in, a dish of mutton is typically served with a bowl of noodles and a bottle of spirits. A special sauce on the side can be added for more flavor.

"Good mutton material is the key to good meals," said an owner of a mutton restaurant on the street. "We use goats that have been raised for up to two years, weighing more than 40 kilograms. The meat will be most tender."

Preparation work begins a day ahead of time. After a goat is slaughtered and cleaned, the meat is put into a pot to boil for two or three hours. Then, the mutton will be stewed for two more hours into the early morning hours. It's then left inside the pot with the lid on to concentrate the flavors.

Baofeng Restaurant is among one of the oldest and most venerable for many mutton lovers. It starts to get busy as early as four in the morning and follows the 100-year-old traditional way of cooking the meat.

The secret recipe lies in the stock. Each restaurant adds secret little ingredients of its own to produce signature tastes. At Baofeng, secret recipe aside, Chef Lin said he adds only water, ginger and salt to the boiling pot to maintain the original flavor of the mutton.

After boiling, Lin removes the mutton chunks, rinses them with hot water and then rips out the bones and excess fat. He covers the mutton with plastic film to retain moisture and let the meat cool down naturally.

The earliest customers at the restaurant are usually the older residents living in the neighborhood. It's a daily breakfast.

"I've been coming here for the past 20 years," said one older customer eating a mutton meal.

Zhuang Tingting helps with the operation of the restaurant, along with her sister-in-law. The women took over after the parents grew too old to handle the business.

She came to Shanghai only seven years ago upon her marriage and already feels a deep bond with regular customers.

"They are our customers and also our neighbors," Zhuang said.

The old street attracts many tourists, and many are curious about this time-honored culinary tradition.

"Boiled mutton tastes pretty good with the proper amount of salt," said a tourist surnamed Hong. "I think I might try out the braised one next time."

Meanwhile, other restaurants in Minhang use sheep mutton.

In Zhudi, restaurants introduce sheep mutton from the city of Huzhou in Zhejiang Province, where the ovines have adapted to the climate of the area and produce mutton of high quality.

Mutton cooking in Huacao, another town in Minhang, also uses sheep – animals that are more than a year old and weigh 30 kilograms. Many herbs used to grow where sheep graze, giving the meat a unique flavor, according to Huang Xinxing, a local folk researcher.

A San Mutton restaurant was opened by Lu Yinfei and his family in 1989. They didn't "inherit" mutton recipes but rather developed their own.

Each large pot at the restaurant stews 200 kilograms of mutton for several hours. Some customers prefer the mutton fresh from the pot to savor the hot, tender slices.

When a customer orders a certain portion of the mutton, Lu slices off the requested portion to perfection.