Well, this is exciting. Getting dressed up, resting elbows on a leather-bound table, gazing out to the Harbour Bridge. Not to mention legions of black-suited waitstaff frogmarching trays of intense, precise, beguiling food towards you for three hours on end, and having to pronounce things such as Chambolle-Musigny once again.

Sydney has waited two years for Oncore by Clare Smyth (pronounced Smith not Smythe), and even now Britain's first female, British-born, three Michelin-starred chef is keeping us waiting. Her people say she'll pop in for a visit to her first restaurant outside Britain some time in February.

Not that she was ever going to be here full-time anyway, pandemic or not. That role goes to New Zealand-born head chef Alan Stuart, who has worked with Smyth both at Restaurant Gordon Ramsay and her own Core restaurant in London's Notting Hill.

Make yourself at home

On arrival on the 26th floor of Crown Sydney, each guest is taken to the kitchen to meet the chefs, who toil away behind glass. Some have no idea how to react to this welcoming gesture; others embrace it.

Like Core, Oncore looks and feels like a luxury residential apartment, with its deeply cushioned bucket dining chairs, long chef's table, blonde parquetry, and Good Food Guides and art deco vases scattered among superfine glassware on the shelved walls.

Restaurant manager Michael Stoddart and the floor team move smoothly among guests, quickly intuiting who needs attention.

There's something of a botanical theme, with strange branch-like fixtures creeping across the ceiling, their flower lamps emitting soft light over just 68 generously spaced diners.

Much of the food comes nestled within bouquets of greenery, which sounds kitsch, and possibly is, but it has great charm. A blizzard of appetisers showcases the kitchen's finesse – the paper-thin quality of the tart beneath a "jellied eel" emulsion, the wreaths of smoke around lollipops of chicken wing, the pea-green cream trapped inside a tiny gougere pastry.

Another tart, of chicken liver parfait under a cloak of madeira gel, must be picked from a gnarly old vine cutting decorated with moss and tiny seasonal flowers like a woodland scene from Bambi.

It's all about the potato

The seven-course tasting menu unfurls through kingfish crudo curled into a flower with petals of radish, loosened by a broth of the kingfish bones. Then it's time for the much-acclaimed Potato and Roe, signature dish at Core since day one in 2017.

An homage by Smyth to her Northern Ireland childhood on a potato farm, it's a truly delicious thing, each whole potato cooked low and slow in kombu butter, then topped with herring and trout roe and tiny fermented potato chips planted among baby shoots of sorrel, chives and rocket.

Grown by the Hill Family in the Southern Highlands, the spud is dense, waxy and briny, with an umami-rich seaweed beurre blanc of perfect nappe consistency (rich, light, but still liquid). Good grief, did I just write the word "nappe"? What's next, the word "cuisine"? This is taking me back to my classical French cuisine days (oops, I just said cuisine).

A fat wedge of treacly, cakey, malt sourdough is brought with a truckle of butter from Victoria's Long Paddock Cheese that sees me saying to the room at large "this butter is so good it doesn't need bread". Lucky the tables are well-spaced.

The fish course is Murray cod, in a broth that is light and herbal. Just as well, because we're about to get meaty.

The meat of the matter

Each dish brings another chef, and another story, to the table. The Lamb Carrot is pretty full-on, a single carrot slow-cooked in lamb glaze to evoke the joys of a real lamb navarin, with a little sheep's milk yoghurt and carrot top pesto puddled in lamb jus. That would suffice, but it's also topped with shredded lamb and lamb fat crumble, and comes with a little bun filled with more lamb. Delicious, but in danger of losing the joy of that carrot.

Another classic Clare Smyth dish is the Beef and Oyster, faithfully recreated here with a perfect square of rare Shiro Kin wagyu crowned with plump, warm Appellation oysters from Wapengo. To the side, a dramatically deep oyster shell is a supposed "pie" of soft beef stew, silky mash and oyster, topped with an oyster crisp.

At this stage, my stomach starts telling me my work here is done. I tell it to buckle up and get serious; the restaurant industry is back with a vengeance.

Three thousand bottles, no waiting

Head sommelier Remon Van de Kerkhof has a great love of Australia's most classically made wines – Pikes, Grosset, Balnaves – and showcases many of them on the wine pairing. Yes, you surmise correctly; we're not in funky, feral, natural wine territory here.

If you're feeling cashed-up, now would be a good time to order the Michel Noellat Village Chambolle-Musigny 2017 ($98 glass/$550 bottle) or indeed, the Comte Georges de Vogue Musigny Grand Cru ($4850).

Sweetness and light

Pre-dessert is a stunning visual play on a toffee apple with a flummery-like Pink Lady mousse encased in apple gel tinted both red and green.

Dessert is a most alluring little concoction reminiscent of a Christmas tree, made of soft and crisp meringue hiding a stunning Poire Williams sorbet and lemon verbena jelly. I love the way it's constructed almost as much as I love the fact that it hasn't been deconstructed.

There are petits fours, too, but I don't want to do a spoiler on every little thing.

The verdict

Oncore is just how I imagined it – completely over-the-top, excessive, luxurious, a tiny bit naff and damn good fun. The food is unapologetically fashioned, formal and playful, honed and honed until breathtakingly consistent by one of the strongest kitchen teams in Australia. It's a "nicer" experience than I expected, and more nurturing. The potato dish alone is worth price of entry.

There's cause to think that sitting down for three-and-a-half hours over seven courses of fine dining at three Michelin star level is unsustainable, slightly absurd and more of an event than a dinner. I defend to the death their right to bring it to Sydney, however. And our right to get excited about it.

The low-down

Cost Three-course a la carte $200pp; seven-course tasting menu $300pp; wine pairing $190pp

Vegetarian Seasonal dedicated menu available

Drinks Champagne by the glass, bespoke cocktails, and 3000-bottle cellar

Pro tip Bookings open 9am on January 1 for March, and will go like hot potatoes and trout roe.

Terry Durack is chief restaurant critic for The Sydney Morning Herald and senior reviewer for the Good Food Guide. This rating is based on the Good Food Guide scoring system.