The country's taste buds could take a hit if changes immigration rules make it harder to hire staff from overseas, restaurant owners say.

An explosion in New Zealand's culinary scene in recent years means the Kiwi diet has expanded well beyond the classic meat and three veg, fish and chips, and pies.

But many of the country's top restaurateurs fear the government's changes will leave them short-staffed and lacking the necessary expertise to keep serving up interesting, innovative dishes.

The government plans to lift the salary threshold for people applying for a work visa under the skilled migrant category to $50,000 a year - which could have a major effect on the hospitality industry.

Sid Sahrawat owns top Auckland restaurants Sidart and Cassia.

Out of the 39 staff he employed, just five were New Zealand-born.

It was already difficult to get good staff locally, with many highly trained New Zealand chefs and other hospitality workers opting to head offshore, Mr Sahrawat said.

"We just can't find enough people for front of house, or kitchen. It's a constant battle to get people who are driven and passionate about hospitality."

The government should be making it easier for business owners to hire and keep migrants on staff, Mr Sahrawat said.

"It's already hard enough for us to try and renew someone's visa ... and to make it even harder, [the changes are] going to be challenging for any restaurant or cafe owner in the country."

Cassia served modern Indian cuisine, so Mr Sahrawat said he needed to hire chefs with particular skills and expertise.

"It's a very skilled job, especially on the clay ovens. It's a bit like a sushi chef who trains for years and years before he gets really good at what he does. It's the same thing, we need people like that to be coming from India."

Lorenzo Bresolin, along with his brother Leonardo, owns something of a food empire in Wellington, including two restaurants - The Bresolin and Scopa - a couple of takeaway pizza joints and a coffee roastery.

About 30 to 40 percent of their staff were from overseas, he said.

"We've done a lot of work with developing the local talent, but we still very much rely on these imports who come here and fall in love with our culture and with our people and it's really sad when they need to go or they're no longer allowed to stay."

There were benefits, too, to having such an international workforce.

"Hospitality looks after everyone, the locals, the tourism market, the visitors, the travellers, and it's incredible having bilingual staff, being able to host international guests and make them feel at home and guide them through the experience," Mr Bresolin said.

There was also a risk New Zealand's tastes could become a little blander, if restaurants became less diverse.

"New Zealand has been years behind Australia, let alone what happens in the northern hemisphere," he said.

"So we probably only end up slowing that development down further if we weren't going to keep our minds and our palates expanding with these humble visitors who fall in love with our nation and want to help us develop," Mr Bresolin said.

Laura Verner from Pasture, a small, fine-dining restaurant in the Auckland suburb of Parnell, said she too had had staff who were forced to leave their jobs because their visas had not been renewed.

"Just recently we had one of our key staff members just turn up with a letter from Immigration and it was absolutely devastating," she said.

The Restaurant Association said it had raised the hospitality industry's concerns with Immigration New Zealand.

Public consultation on the government's immigration changes closes next month and Immigration Minister Michael Woodhouse intended to have them in place later this year.