Whatever you say about posh new bistro Duck, its proprietor, experienced Chinese-New Zealander restaurateur Dah Lee, is a brave man. By touting $40 steak and wine prices that can fly to $136, he’s betting that Phnom Penh's well-heeled have been waiting with their forks – and wallets – out for a taste of the good life.

A few years ago, Tonle Bassac would have been an odd choice for one of the city’s priciest restaurants. Today, its leafy, café-rich streets offer an increasingly pleasant neighbourhood. And with indie-film bastion Meta House, Cambodian odds and ends concept store trunkh, and a falling-down slum building that serves as a haven for local artists, the area’s got boho credentials – with all the problems that boho credentials create.

There’s no question about it: there’s something uncomfortable about tucking into a $40 Wagyu steak opposite the White Building – if they sit outside, Duck diners can see the entrance to the slum.

I was spared, sort of. When I visited, there was no Wagyu at all. Because the demand is so small, they keep very small quantities in-house – it’s imported from Queensland, Australia, and has a marble score of five, meaning the fat is suitably marbled to qualify as Wagyu. The scale goes up to 12.

(In reality, Wagyu beef itself is a bit of a myth. Often understood as synonymous with Kobe, the premium cut, the phrase Wagyu, means little more than “Japanese cattle”, or, in practice, “a cow that is a bit Japanese”. I could send a motley crew from London for an extended holiday in Kyoto, and if they shacked up with the locals, their kids could be called “Wagyu”.)

The other problem is that there is nothing very boho about Duck itself. There are paintings by local artists on the walls, Amy Winehouse on the speakers and an attractive white sign on the front door, but the crowd contains – as far as I have seen – more well-to-do businessmen than artsy types. A man with his tie pompously tossed over his shoulder prompted a discussion about dining etiquette. Posh enough to pay $100 for a meal? Posh enough not to spill steak juice all over your shirt.

The menu – if you can make it out in the excessively dark room – could be more creative. Given the name, I had expected an Asian influence. There were other surprises. Get this, there’s no duck to be found.

Without the Wagyu as a choice, I tried the other two steaks – Angus and filet – rack of lamb, mushroom risotto, Greek salad and pork belly.

Newton, the head chef, has more than 25 years in New Zealand and Australian kitchens, and his menu is simple, hearty and – for the most part – delicious.

Pork belly was tender with a nice pang from the hoisin reduction accompaniment.

The Black Angus sirloin steak was a nicely cooked but slightly fatty piece of meat, served with a wine-rich reduction and a bowl of more-ish, thick-cut chips. Flown all the way from Australia, the $20 cut was no more spectacular than a $12 steak from other French-inspired Phnom Penh restaurant menus and could have done with some crunchy baby carrots or buttery greens to cut through all the rich protein.

Far better was the filet ($20), served crisp on the outside but deliciously tender underneath, with a creamy, flaked potato gratin.

The small Lamb shank ($19) packed a big, juicy punch, and was nicely complemented by spinach and shallots, while mushroom risotto proved tasty but, like most risottos, needed something light and fresh to break up the thick monotony.

Dessert ($4.50) was good but uniformly rich, given the heavy meals that preceded it. A creme brulee gave a satisfying crackle and revealed an eggy custard. It was accompanied by a sliced lady finger banana, with the cut side coated in a film of golden toffee. Delicious, but local fruits could have had a look-in on the small desserts menu. The chocolate mud cake was more of a pudding, with a rich molten centre, a pot of whipped cream and small serving of syrupy berries, which shot the overall sweetness up to overwhelming levels.

The bill came to around $100 for three people for a bottle of the house red ($23), three mains, a salad and two dessert. Ouch. Mains – if you include pasta – start at $9 and red meat from $19.  By the time the bill came, I was truly glad the Wagyu was out.