Nose-to-tail – the practice of eating the whole animal, including offcuts and offal – is a concept that’s been around in the dining world for a decade or more.

Seafood, though, has been another story. It wasn’t until chef Josh Niland came along that the fin-to-scale movement began to gain similar traction.

The visionary Niland, who moved from Maitland to Sydney to fulfil his dream of becoming a chef when he was just 17, started his career in the kitchens of leading Sydney restaurants including Glass Brasserie, Est and Fish Face. In 2016 he and his wife Julie opened Saint Peter, where they set about elevating the fish dinner.

“I wanted to have a really nice space to have an all-fish menu and have all-Australian ingredients and an all-Australian wine list,” Niland tells Broadsheet. “I want to show off how good fish in Australia can be.”

From the start, sustainability has been central to Saint Peter’s menu. One of the biggest issues in the seafood industry is waste, says Niland. Accepted wisdom says you get 40 per cent yield from each fish, he explains. Another 10 per cent – mostly bones – can be used to make stock. What to do with the remaining 50 per cent became Niland’s focus. After locking himself in “a really small room in Paddington and only doing fish” for two years, Niland developed dishes and techniques to use parts of the fish that are traditionally discarded – “the blood, or scales, or bones, or head, or even certain muscles in the head” that he didn’t previously know existed.

Niland’s fin-to-scale philosophy has resulted in some innovative dishes, from Saint Peter’s infamous fish-eye chips to Spanish mackerel dry-aged for 20 days, which Niland says tastes like mushrooms, yeast and baked bread. “The secondary cuts need a bit more work and … time to create, but it means we produce dishes that are beyond the fillet,” he says. “That’s more interesting for our guests too.”

It means that at Saint Peter, the fish always comes first, says Niland. “When any fish is delivered, we set out to use almost every single piece. From how we remove the scales and what we can do with them, to the eye, cheek and tongue; every bit is considered for its texture and taste and what we can use it for, both individually, or in combination with other ingredients.

“I recently broke down a 4.2-kilogram sea bass. Once I had finished butchering, there were only 175 grams of waste left at the end. That’s almost a 96 per cent yield from one fish. That doesn’t just mean fish stocks could be more sustainable, but hospitality businesses could be too.”

Underpinning Niland’s sustainable fin-to-scale approach is respect, he says. “Fishermen risk their lives every day to land fish for us to buy. If we kill any animal to produce food, we should be duty-bound to use as much of it as we can. We more or less do that with cattle and pigs already. It’s about respect for the planet and everything that grows and lives on it. What we take from the oceans and seas should be treated no differently to what we take from the land.”

Niland works with several suppliers, including Nicholas Seafoods at the Sydney Fish Markets. “Nicholas has an employee there named Tony Worth who I’ve worked with for seven years. He sends me a text message every morning to tell me what fish he has,” he says. “That tells me who the fisherman was and where it was caught and how much it costs, and you can usually make really good decisions around that information because Tony’s got a great eye and he sends me photos as well of the fish that he sees.”

Home cooks keen to make their seafood consumption more sustainable should check threatened species lists and look for alternatives to the traditional fish fillets. “Look at smaller fish and what you can do with them,” says Niland. “They’re often more nutritious anyway.”

In 2018 Niland opened the Fish Butchery, a retail space 10 doors from Saint Peter. The two venues, together with a crop of nearby bars and restaurants including Fred’s, 10 William St and The Stables, have made Paddington one of Sydney’s dining hotspots.

“In the three years we’ve been here it’s really evolved. I was initially interested in the area because there were some amazing and successful operators already here. So, I knew there was a market and felt confident the area was on the up,” says Niland. “It’s a great place to spend an evening.”

This article is produced in partnership with City of Sydney. Follow and use the hashtag #sydneylocal on Instagram for more local secrets.