My palate memory gives me a quick kick in the ankle. You've had this before, it says. I look down at the pretty flower formed by petals of finely sliced Hokkaido scallop carpaccio ($19), lightly seared with brown butter, dressed with soy, and strewn with salmon caviar.

So I have. It was the go-to dish in my review of Kerby Craig's Ume in Surry Hills in 2012, and it's as good now as it was then.

And yes, Ume's then sushi chef, Yang Wu, who trained under Kenji Nishinakagawa at the sadly missed Koi in Woolwich, heads up the kitchen here at Katsumi. Welcome back, scallop carpaccio, we missed you.

It's not every day that you get to drink a delicious lychee gin and tonic and nibble an excellent tempura prawn sushi roll while listening to Van Morrison's Into the Mystic, down the breakfast pointy end of Tennyson Road in Mortlake, but there you go. Where there is good food – and G & T – I will be there.

Katsumi opened its doors on the site of the former Grand Terrace restaurant in November 2017, having Japanesed the Chinese-themed interior with blond timbers, a private dining room and a long, low series of fish tanks that serve as steps to a raised dining level.

General manager Armando Favrin brings a steadying hand to the young wait staff, as groups of locals drift in to drink at the bar or sit out on the balcony overlooking the street.

The menu is a curious mix of classic and fusion, from agedashi dofu to twice-roasted duck breast with mushrooms and barramundi with artichokes and balsamic soy sauce.

With Yang Wu on board, anything raw is a treat. The chef's selection of mixed nigiri sushi ($19) is meticulous, the fish generously draped over hand-warmed rice – although the sweet-natured waiter has less idea of the individual fish than I do.

Follow that with a top-value tempura prawn sushi roll ($14), the prawns still warm and crisp from the fryer, and you'd go home happy.

The fusion menu is seemingly designed to appeal to those who would rather be anywhere but in a Japanese restaurant.

Grilled octopus legs come with smoky Japanese aribiki pork sausages, baked kipfler potato chips and a whippy salsa verde puree ($21) in a Jap/Italian hybrid that is lost in translation.

A rack of very nice Thomas Farm lamb from South Australia ($34) is char-grilled and split into individual pink-hearted cutlets, served with oddly shaped carrots, overly frazzled brussels sprouts, potato and cauliflower puree and a rough edamame and avocado crush.

It's all very meat-and-three-veg, complete with a sweet miso mint sauce that makes it feel like you're eating a Sunday roast in a ryokan.

Desserts are pretty and precise, although a layered millefeuille of green tea crepes ($15) sandwiched with yuzu cream – quite a lot of yuzu cream – never quite transcends the fact you're eating a lot of yuzu cream.

At weekends, it gets ever more curious, as high tea and brunch menus mix East and West, from salami and avocado crostino to eel donburi and teriyaki chicken, with espresso coffee a feature. Crazy stuff, huh? It's all a bit wacky, but the care and the flair are there; and anything raw is the place to be.

The low-down

Vegetarian Several salads, vegetable tempura, and eggplant and mushroom mains.

Drinks Boutique Australian wines, the big three Japanese beers (Asahi, Kirin, Sapporo draft), around 20 sakes, and fun cocktails.

Go-to dish Scallop carpaccio with butter soy and salmon caviar, $19.

Pro tip The seasonal cocktails can also come as mocktails.

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.