Fifteen Cornwall in Watergate Bay, one of the last outposts of Jamie Oliver’s restaurant empire, is still open for business.

Owned and run by the Cornwall Food Foundation charity (CFF), Fifteen Cornwall trains six to 10 young unemployed people a year in its kitchens while serving up largely locally sourced seasonal food.

The celebrity chef’s Jamie’s Italian restaurants may be now be history, with the business in administration and 1,000 staff made redundant, but the seaside charitable venue he opened 13 years ago is preparing for the graduation ceremony of its latest cohort of trainee chefs on Monday.

When news that the 25-restaurant Jamie Oliver Restaurant Group, which included Jamie’s Italian, Barbecoa and the original Fifteen in London, had collapsed on Tuesday, fans of the Cornish outpost feared the worst.

The restaurant’s website crashed under the weight of visitors and it took 140 calls from diners checking their bookings.

There were also questions at a Cornwall council meeting, as the charity employs nearly 100 people in the county, three-quarters of whom work at Fifteen itself. It has trained 130 apprentices since it launched in 2006, two-thirds of whom are still working in the restaurant trade, and many have set up local businesses, making it an important part of the economy in a county where regular work can be hard to find.

“Nobody was worried about their job as we made great pains to make clear we were not affected,” Matthew Thomson, the chief executive of CFF and Fifteen Cornwall, told the Guardian. “But it was an enormous thing to comprehend. People were wide-eyed, there were tears. We’ve got high staff retention here and there are lots of people who Jamie keeps in touch with.”

“We have really been touched by the amount of goodwill that has been expressed and the recognition that we are carrying on.”

While the Jamie Oliver name is above the door under a licence agreement and the restaurant shares a name with the chef’s original London establishment, Oliver spends only very occasional days in the kitchen working with apprentices and has no financial involvement.

The news about the demise of Fifteen in London was a particular blow as Thomson had been in talks with Oliver about building closer links with the restaurant, which originally inspired the Cornish outpost.

Historically, trainee chefs from the London establishment have done a stint in Cornwall and Thomson says there are chef jobs on offer in Watergate Bay for anyone willing to relocate from the capital.

Thomson is hopeful more can be done. “We are looking for ways to extend our impact. If that can involve reaching out to renew Fifteen in London I would love to find a way to make that happen.”

“It would be a beautiful fairytale moment to achieve,” he says.

But Thomson admits that Fifteen Cornwall has its own battles to ensure it can honour its existing commitments, taking on its 15th group of apprentices this autumn, during tough times for the restaurant business.

The restaurant made sales of about £3m last year, but only broke even, after making an average profit of more than £200,000 a year for several years. Thomson says trade can be tough outside the school holidays.

Fifteen has undergone staff changes since 2016 in an attempt to cut costs, as the number of diners has slipped back from its heyday of about 80,000 a year to to less than 70,000 now.

Just like Oliver’s main business, Fifteen Cornwall has suffered as the number of people dining out at restaurants has fallen back as a result of Brexit and economic uncertainty. Thomson admits he has also made mistakes, letting a popular head chef with his own following go in one of the restructures.

“It’s a massive restaurant and you wouldn’t build it this big now. The market has shifted considerably since 2006,” Thomson says.

“The kicking that Jamie has got around his restaurants over the last few years has also had an effect. Fifteen’s uniqueness was lost in the clamour about Jamie’s Italian,” he says.

But he says there are still plenty of Jamie Oliver fans and the chef remains a big asset for the charity.

“His energy is undinted. He wants to keep on making good things happen and I’m trusting we will work together. Maybe we will get a bit more of him in the future. He should be proud of what he has achieved.”