The inside scoop on one of Sydney's busiest restaurants, Chin Chin

Eleven months – that's how far in advance one diner made their group booking at Sydney's Chin Chin. Another guest scheduled three back-to-back Tinder dates from her table in one night. Then there's the way staffers are besieged by relatives and friends-of-friends hoping a special connection might get them into Chin Chin. "Literally, as we were sitting here, my mum just texted me and asked, 'Hey, can we get a table for 22 people, hope your day's going well!'" says one employee as I'm interviewing her for this story.

There's something about Chin Chin that inspires hyper fandom and interest. The Sydney outpost of the popular Melbourne restaurant only opened in Surry Hills in October 2017, and nearly 100,000 "Feed Me" banquet menus have been served in that time, while kingfish sashimi is the number one dish (more than 22,000 have been ordered). "We go through six 30-litre kegs of riesling a week," says head sommelier Jacqueline Turner.

• Terry Durack's Chin Chin review

Assistant manager Sophie Adams is well-trained for how intense it can be: she started at the Melbourne restaurant, where "you lose your voice every night" from the high-volume handling of diners. And that space, launched in 2011, is smaller than Sydney's location. At the Surry Hills site (once you include the in-house Go Go Bar and the Chi Town event space downstairs), guest numbers can jump to 1500 in a day.

In contrast to the frenzy, a day at Chin Chin starts quietly at the un-party-like hour of 7am. Kitchen manager Max Mullins arrives and ensures the deliveries are received. "The production kitchen crew starts at seven and they are responsible for the bulk of all the prep for the restaurant," says chef Graeme Hunt. This means cooking curry pastes, braising meat and tending to sauces.

"The first job of the day is to get the roast pork belly on the rotisserie and to light the charcoal pit. The pork takes over two hours to cook," he adds. The (ultra-fragrant) sorting of Thai basil, coriander and mint is another major task. "We pick over 10 kilograms of herbs each day," he says. By the week's end, the kitchen clears 200 kilograms of kingfish for sashimi and a literal tonne of protein – from wagyu shins to chicken thighs and lamb shoulders.

General manager Emilio Basone checks in at 8am and has a quiet hour before phones start ringing and the reservation inquiries pile up. "Then it kicks off: all the staff and managers come through and then we're open from 11.30."

Chin Chin's all-day dining schedule means the pace is relentless. Diners start lining up as early as 4.30pm for dinner. A Monday is as popular as a Saturday. "The restaurant will fill up every day." Like clockwork, it's at full capacity at 6.30pm.

This isn't surprising given the original Melbourne location on Flinders Lane attracts such OTT enthusiasm. Serena Williams once ate there 14 times over a 28-day period. As she was in town for the Australian Open – and had important matches to train for – they waived her wait for a table. "There are a few ways to skip the queue," says marketing manager Holly Lucas. Being Serena Williams is one.

Another way? Call the Melbourne restaurant and say you'll drive straight from Sydney to eat there that night – can you get a table?

This happened before the Surry Hills offshoot opened and such road-trip-embarking dedication was hard to refuse. "We said, 'Look, don't tell anyone, but we'll get you a table. Just say my name at the door and I'll come and get you'," recalls Lucas.The eager diners gunned it to Melbourne and arrived around 8pm. "We sat them down and they had dinner and they drove all the way back," says Lucas. That's basically 20 hours in the car to eat pork roll-ups and massaman curry with braised brisket.

"One couple loved Chin Chin so much, they came here on their wedding day," says Chris Lucas, who founded the restaurant and recalls seeing a couple dining there in July 2013. She was in her bridal gown, he was in a tux and they were incredibly young, just married, alone and with little money to their name. He congratulated them with champagne and bought them lunch. How could he not? The bride told him Chin Chin was her favourite restaurant.

Chris never planned to open in Sydney – until he drove past the historic Griffiths Tea site in Surry Hills. The century-old, Flatiron-shaped structure had been vacant for decades, but he convinced the 90-something owner to sell it.

"It was like a time capsule," the restaurateur says, remembering his first walk inside. There were 10-centimetre-thick cobwebs everywhere, making it impossible to look out the windows. There were abandoned sewing machines and buttons on the floor. "There were pieces of paper on the desks from 1971."

It's hard to believe, when you see how bright, airy and ultra-modern the refurbished Chin Chin is.

The restaurateur was keen not to create a carbon-copy of the Melbourne location.

That's why Chin Chin employed "a Sydney designer, Sydney staff, a Sydney chef" for the Surry Hills site.

"Sydney is more outgoing, let's make it more poppy, make it more reflective of the city," Chris Lucas told George Livissianis, the interior designer. A neon-pink bunny – a larger version of the symbol that brightens the Melbourne site – illuminates the Sydney reception.

The menu is more seafood-dependent and vegetarian-friendly, which reflects local appetites and climates. And the Sydney event space (which hosts everything from holy communion get-togethers to neighbouring parties that end up joining forces in loud renditions of YMCA) will be replicated in Melbourne. It'll be launched in early 2019, above the Flinders Lane dining room, with chef Benjamin Cooper installing a rotisserie, roasting ovens, woks and fryers upstairs.

While he's Melbourne-based, Cooper regularly collaborates with Sydney chef Graeme Hunt on the Surry Hills menu. And in this city, the appetite for Sydney-only dishes (such as pumpkin satay) has been matched by an insatiable thirst for rosé.

"It's insane. We couldn't keep it cold enough," says Turner. "We had to rework the entire fridge system in the whole space and get an off-site cold cellar to keep it rolling in." They open 500-plus litres of the wine a week.

Perhaps this boozy demeanour is in keeping with local behaviour. "In Sydney, people are more out there," says Chris Lucas. Sure, there was the time Gordon Ramsay danced on the tables at the Melbourne restaurant, but the Surry Hills location generally has a looser vibe. Whenever Chris turns up, everyone bursts into the YMCA. (People really are into doing the YMCA at Chin Chin.) He suspects the bigger room and packed tables incites people to join in. Holly reckons the Sydney lockout laws inspire people to party a lot harder and earlier – to beat curfew – whereas the Melbourne site has a 3am licence and isn't the end-of-night option for everyone.

When things finally wind down in Sydney, the kitchen employees are last to leave for the day. They ensure the kitchen exhaust is switched off, record all the fridge temperatures and leave the beef brisket, wagyu beef shin and lamb shoulder to be braised overnight. Lists are checked, phones are put in night mode and doors are locked.

The pink neon light of the Chin Chin bunny goes out – but only for a few hours, before it's fired up again the next day.