At his debut restaurant, Sushi On in Kew, chef Yong Hyun talks to every customer at the 12-seat counter where he prepares impeccable nigiri as part of omakase tasting menus. For his second venue in the heart of the city, he’s changed gears, serving quick weekday lunches while still raising the bar for casual Japanese dining.

Sushi On Little Bourke is at the base of the revamped 500 Bourke building (also home to Silk Spoon, MoVida Aqui and Rosa’s Canteen), surrounded by dozens of other office towers.

“It’s not omakase, it’s more like a canteen,” says Hyun of the venue, which opened on February 26.

The lunch menu reflects that, with Japanese sandos, four hot dishes, a few snacks and a bracket of sushi.

These aren’t your regular lunchtime hand rolls, though. Hyun chose a rarely seen sushi called hako, which is made using a wooden mould that compresses rice, fish and garnishes into a neat rectangular block that can easily be sliced into pieces. He says hako sushi holds up much better than the nigiri served during most omakase menus, making it perfect for takeaway.

“If I was to do an omakase but in canteen version, it would not be good quality,” Hyun says.

Even at his more casual venue, the chef won’t cut corners. He uses the same fish supplier, Oceania Seafood in Footscray, as two-hatted Sushi On, and experimented with several kinds of rice before choosing, surprisingly, SunRice. “Excellent sushi can be made with Australian rice,” he says.

Among the seven different toppings on the hako sushi, there’s torched scallop with yuzu pepper; jalapeno and mayo; paradise prawn with nori mayo and rice cracker; and avocado, tofu miso and sesame for vegetarians.

It’s not omakase, it’s more like a canteen.

Yong Hyun

Sandos are filled with katsu pork or chicken, tempura fish or crumbed prawn. Each one is made with brioche and spread with a different riff on Worcestershire sauce, from sriracha to wasabi.

Larger dishes geared to dine-in include wok-fried udon noodles with spanner crab, and tempura-battered fish, cut to chopstick-ready portions and served with chips and wasabi aioli. There are also oysters, sake, beer and a brief wine list for the business lunch set.

A dinner menu that launched on Monday night, will omit the sandos and add sashimi and more mains, including scotch fillet with soy-based steak sauce, tofu-sesame sauce, and charred lemon.

The 50-seater is bright and calming, with a minimalistic fitout of plywood, textured walls and orb-like pendant lights. Hyun hopes to see the same faces several times a week.

“I wanted to make something like Sushi On but a different version, so a lot of people can feel free to come in,” he says.

Lunch Mon-Fri; dinner Mon-Fri.

3/500 Bourke Street, Melbourne (enter via Little Bourke Street), instagram.com/sushi.on.littlebourke/