Quick, pinch my napkin. Is this real? Have we made it? Am I actually here? After months of trying to land a booking at one of Sydney's most popular omakase restaurants, is it finally time to experience a level of seafood that can cause fellow food critics to cry in fatty tuna rapture: "Blessed are we for this sliver of moderately dry-aged fish!"

Kuon Omakase opened two years ago in Haymarket's neon-tinged Darling Square which, depending on who you talk to, is either a soul-sucking boil on the rear end of Chinatown or a family-friendly precinct for bubble tea and Pancakes on the Rocks.

To plonk your own rear end on one of Kuon's nine seats you need to be hovering over its website at midday on the first (but sometimes fourth) Tuesday of each month when reservations open a few weeks in advance. Refresh, refresh, refresh. Click, click, click. Refresh. Click. Refresh. Click. Throw laptop at wall.

Infuriating booking systems are a hallmark of Japanese omakase restaurants, which have been popping up like mushrooms after a downpour over the past two years. The set-menu format – usually about 20 small fishy things for north of $150 – is a smart way to lock in customer spend and staffing requirements. It's also a fun and mindful way to eat.

After more than a year of failed attempts, I manage to secure a Tuesday night spot at Kuon's elegant, blond-wood counter. It's a calming, sparsely decorated room that says, "You're here to pay attention to the chef hand-moulding each piece of sushi." One very attentive waiter clears plates, pours wine and shows guests to the loo across the laneway.

Before nine mouthfuls of nigiri (raw fish served on vinegared rice), there's a procession of free-form creations that showcase head chef Jun Miyauchi's skill at assembling pretty things on nice plates. Seared scampi is a highlight; sweet and delicate and served with perilla leaf and a hunk of avocado, it requires a Certificate IV in Chopsticks to pick up on your first go. 

Steamed chawanmushi custard is a warming lucky dip of dried scallop, turnip-like lily root, edamame and corn; ponzu butter adds lustre to a jumbo Pacific oyster served in a shell that looks like a souvenir ashtray; wagyu tenderloin with fatty monkfish liver – the foie gras of the sea – is enhanced by a lick of red vinegar-based sauce. Is it delicious? Oh, yeah.

I'm less taken with the optional $25 course of tempura sea-urchin gonads. While I've had the occasional spiritual moment with sea urchin when it's served fresh from deep waters, much of the stuff served in restaurants seems to be chefs having a laugh: "Hey, let's see how much we can charge for this kraken snot that tastes like a fishmonger's armpit." 

Then it happens. The alpha. The omega. The imperador nigiri. Crowned with a daub of salted kelp, it's a moment of balance and harmony and pure essence of the ocean, the buttery New Zealand fish firm and sweet against each al dente grain of rice. The heavens open and Gabriel's trumpet blasts. Lo and behold, this perfect piece of sushi.

If you're into this sort of thing, these 10 seconds of bliss really help to justify the $230 price tag.

Unfortunately, the imperador was absent from the menu a week later when I sent a photographer as Kuon only uses the best seasonal catch of the day, et cetera, et cetera. Bermagui-caught bluefin tuna is a little more consistent though, and almost as wonderful.

Miyauchi serves three cuts of the noble fish on my visit: marinated ruby-red akami (lean meat from the tuna's back); luscious, highly marbled otoro (from the fattiest part of the belly) and chutoro, a pale-pink, medium-fatty cut with a flavour that pings every pleasure receptor.

There's also pearly-white southern calamari dotted with caviar, meaty scallops that melt on the tongue, and the sweetest of prawns from New Caledonia.

Many of the jewel-box morsels are seasoned with nikiri, a secret soy blend brushed just before serving.

Qualms, I have a few. The only white wine by the glass is a dry and textural 2019 Grace Koshu Toriibira from Japan and it's $27. Sake is better value, but still far from a bargain.

But, well on my way to becoming one of Sydney's many omakase fanatics chasing seasonal fish and signature specials, I will absolutely return.

How does Kuon stand up to Yoshii's Omakase at Crown which is – wait for it – $350 per person? I'll have to let you know when I've landed a bloody booking.

Vibe: Revered sushi temple for delicious moments of zen

Go-to dish: Bluefin tuna otoro (as part of a set menu)

Drinks: Short and pricey list of mostly French whites, one red and lots of sake

Cost: $230 per person for a 20-course omakase menu

This review was originally published in Good Weekend magazine