"It is truly ingenious and enterprising of these Chinese restaurants to be turning what would otherwise end up in the bin into sought after delicacies," said Associate Professor Henry Chung, a China marketing specialist.
"The restaurant is very competitive, and these businesses are showing not just product differentiation but also cost leadership."
Chung said it is not uncommon for Asians to eat heads of animals and offal, and in many cultures they are highly sought after.
"In Asia, sometimes heads are even more expensive than the meat, but in New Zealand these businesses can get them literally at throw away prices," Chung said.
"So it's brilliant that they can turn them into premium items on their menu."
Chung said re-cooking turning food waste into a second course also created a "value add" to the original meal.
Sun World co-owner Joe Lam, 39, said he got the idea from how Peking Duck, which is traditionally eaten in three stages.
The duck is usually carved in front of the diners and the skin is served dipped in sugar and garlic sauce.
The meat is then served with steamed pancakes, spring onions and sweet bean sauce and the remaining fat, meat and bones are turned into broth.
"Things like scampi and crayfish are not cheap, so I feel it is such a waste when customers eat the meat and throw away the head," Lam said.
"So we follow the Peking Duck style and turn them into something delicious in the kitchen."
A large platter of scampi can set customers back $380 at the restaurant.
Here, the bits from uneaten crayfish heads are also scraped out, steamed with egg and served as a second course custard dish on request.
Restaurant regular Wu Weiming, 57, who moved to New Zealand from Guangzhou two years ago, said the second courses were often "more delicious" than the first.
"The first course is what we ordered, so we know what to expect," Wu said.
"But the second course is invented by the chefs, and it takes creativity and also brings an element of surprise."
Wei Fu Restaurant chef Qinghui Gao said fish head is considered a delicacy across China, especially in the Sichuan region.
"Chinese people consider it the sweetest and most flavourful part of the fish," Gao said.
"You have to be careful with the bones but the more you suck the more flavours you get from the head."
He said the best way to eat a fish head is to start with the delicate meat on the cheeks.
Then go for the more gelatinous bits on the jaw and tongue, before chewing down the crunchy eyeballs.
According to Gao, fish head is also very nutritious, providing a great source of protein.
Massey University sociologist Professor Paul Spoonley said access to familiar food was an important part of settlement for migrants in a new country.
"Eating authentic food is very important to them," Spoonley said.
"The number of Auckland's ethnic and immigrant communities are also large enough now for restaurants to cater to them."
