Margaret River, WA: Koomal Dreaming's Indigenous food tour enthralls chefs Rene Redzepi and Tetsuya

Josh Whiteland isn't a chef, but he has some intriguing culinary experiences on his curriculum vitae. Over the years, the cultural custodian has carved a didgeridoo for kitchen goddess Nigella Lawson, escorted Tetsuya – the chef-owner of the eponymous Japanese restaurant – on a salmon fishing trip, and introduced Rene Redzepi – of Noma in Copenhagen fame – to the joys of eating and cooking abalone "properly".

So successful was this latter interaction, Whiteland was invited to Redzepi's acclaimed MAD food symposium a few years back. The Whiteland-inspired abalone recipe reportedly still makes a seasonal appearance on Noma's menu.

The Busselton, Dunsborough and Margaret River areas of Australia's beautiful south-west corner are Wadandi and Bibbulman country. Whiteland is a Wadandi man, a traditional owner. When he's not sharing his indigenous know-how with visiting culinary stars (who, incidentally, come to town for the Western Australia Gourmet Escape food festival), he is imparting his in-depth cultural knowledge to guests on one of his Koomal Dreaming Cultural Experiences. I'm signed up for the Ngilgi Cave Cultural Tour that includes a descent into one of the mesmerising limestone and granite caves typical along this coast. We also get to taste native ingredients, tap into bush medicine and meet the animals and plants.

Whiteland is traditionally known as Koomal, the Wadandi word for his totem, the brushtail possum. I join him in brushtail possum country not far from the cave. Standing on a sandy track encircled by native bush, he gives our small group a geography lesson. Scraping lines and crosses in the dirt with a stick, he maps out the coast, and, alongside it, the limestone-granite ridge that stretches more than 100 kilometres from "from Cape Naturaliste all the way down to Cape Leeuwin". He circles the areas of karri forest – "the third tallest tree in the world, full of oil and good for medicine", and the lagoons "where big tidal movements mean you can fish for abalone, octopus, fish, crayfish and draw large reef fish into the shallow water with a spear".

His calm, resonant voice keeps us enthralled. "Melaleuca are traditional trees that the Wadandi still camp underneath," he explains. "They block the heat of the sun, and the wind and the rain, and it's nice and soft underneath, nothing grows." He pulls leaves off a peppermint tree – or "wannang" and crushes them into his hands. "Rubbing the oil into your skin gets rid of the insects and mosquitos ... You can also make tea from the leaves – it's good for your chest at night time, and if you chew on the leaves it gets rid of any bacteria in your mouth."

We walk on and see the squiggle-and-line footprint of a lizard in the sand and the abandoned hole of a snake recently moved into the safety of the surrounding national park. Whiteland lifts up undergrowth to reveal unripened sugar berries – "bush candy similar to a native berry", and points to bark "that makes good ropes" and leaves "that work well for traditional dress". He explains that there are six seasons in the Noongar (the Aboriginal groups in the territory stretching from Kalbarri to Esperance) calendar and that the bush lets you know when the season is changing. "The inji bush, a red flowering plant, dies off as our spring comes," he says. "And if the possum bush is still blossoming it means the marsupials are still carrying their young in the trees, so we leave them alone."

Ngilgi Cave is named after one of the Wadandi people's dreamtime spirits. It is one of only seven "show" caves open to the public. On a wooden staircase we descend into an other-worldly place where little lamp-lit steps and trails wind around hundreds of waxy stalagmites and gloopy stalactites. At the bottom of the main cave, Whiteland plays his didgeridoo, the haunting sound reverberating around the natural amphitheatre so that we all fall into respectful silence.