Lotus head chef Kenji Okuda to fly solo with Koku Culture Cafe, Ashfield

Lotus Barangaroo head chef Kenji Okuda is moonlighting in the most cheffy way possible. On his day off, Okuda stays up all night making miso and soy sauce from scratch because he maintains he finds alchemy in the combination of Sydney's early morning temperature and the complicated science involved in its production.

He's also been quietly hatching another project on the side. Okuda will depart Lotus at the end of April, opening Koku Culture Cafe in Ashfield next month. Okuda's new venue will be a savoury version of Willy Wonka's lair, part Japanese-inspired cafe with a sideline in house-made Asian staples.

The chef – a member of the kitchen team at Billy Kwong before joining Lotus – visited manufacturers in Japan to learn the art of soy and miso production. "I'm making a fully organic miso paste, which we'll sell and also put on the menu at Koku when we open. I'm planning on doing a smashed avocado with shiso and miso dressing," he says.

Koku will slide into 355 Liverpool Road, a site previously occupied by a Chinese restaurant. And if its chef-owner looks a little weary, you'll know he's just finished a production run. "You've got to keep mixing the soy for 10 hours. It is very labour-intensive but worth it. When I make miso it is not much different. I still have to wake every three hours."