Fish-eye crackers? Before Josh Niland opened Sydney restaurant Saint Peter in 2016, we’d never heard of them either. Nose-to-tail and root-to-stem cooking are mainstream concepts, but Niland is a pioneer of fin-to-scale, which entails using almost every part of the fish. In advance of the release of his new book, The Whole Fish Cookbook: New Ways to Cook, Eat and Think, we asked the chef for three easy ways to use cuts that are habitually tossed out.

John Dory livers
At Saint Peter Niland serves John Dory liver on a crumpet for lunch. It has a wonderfully meaty flavour with the texture of silken tofu. At home they can be crisped in a pan and served on toast. First pat the livers dry, then dust lightly in rice flour and pan-fry in ghee until golden brown on the outside but still pink inside. Finally, season liberally with salt, pepper and lemon juice. Serve on toast with parsley. Ensure your fish has been carefully handled and gutted, without using water. Livers should be firm to touch with no fishy smell or imperfections.

Fish bone marrow
Ask your fishmonger for the spine from swordfish, mahi mahi or wild kingfish. The spine will slice into small sections easily when you cut between each vertebra. Once separated, season with any spices you like, plus salt and olive oil. Place on a baking tray and roast at 220 degrees for 10 minutes. The heat will liquefy the marrow creating a sticky, buttery, delicious mess in the bones. Deglaze the tray with lime juice, olive oil and fish sauce, poured over the bones. Niland recommends diving straight in with your hands to suck the marrow out.

Fish milt
Milt is male fish roe, or semen. Niland says it can be texturally challenging for many people, but it’s easy to fall for once you’ve tried it. It also makes a damn good schnitzel sandwich. Slice the milt into two-centimetre-thick medallions, coat each in flour, dip in a beaten egg and cover in breadcrumbs. Pan-fry the schnitzels in ghee until golden brown. Season with salt and pepper and serve on soft white bread with tartare sauce. Much the same as the fish liver, milt should be firm with no imperfections or smell, and bone-white in colour.

The Whole Fish Cookbook: New Ways to Cook, Eat and Think by Josh Niland is available from September 1.

This story originally appeared in Sydney print issue 19.