Fanny Chan wanted something memorable to add to her pralines, and she found it in a Sydney specialist food shop: Tasmanian mountain pepper berry.
"In Europe, we always talk about Espelette pepper from France or sansho pepper from Japan," says the Belgian-trained chocolatier. "I wanted to have something that was unique to Australia."
The pepper berry's minty bite, she realised, perfectly countered the sweetness in a strawberry and white chocolate praline. This dynamite combination ended up at Boon Chocolates, the Darlinghurst shop she opened with her brother, Alex, in 2008.
Nearly a decade later, the siblings have rebranded their shop as Oh! Boo Chocolates and moved to Sydney's Barangaroo district, but the pepper-berry praline - a red, jewel-like dome - remains in their range, which will now feature more creations with indigenous ingredients.
The pair's renewed interest in native produce comes following a recent bush-tucker tour at the Royal Botanic Gardens with Aboriginal education officer Jody Orcher, where the Chans encountered finger lime, and crushed aniseed myrtle leaves in their hands to discover the plant's liquorice profile. A growing relationship with Sharon Winsor of Indigiearth has also given them a stronger understanding of the ingredients found in Australia's landscape. Winsor's company - which prides itself on its Aboriginal ingredients that bring "60,000 years of culture to households across the world" - has supplied Oh! Boo Chocolates with a range of palate-broadening native products.
"This will be the first unique collaboration with a chocolatier," says Winsor.
The variety pack that she has given the Chans includes everything from quandong ("a native peach found in dry desert and arid areas") to bunya nuts (from trees that "usually don't produce a crop of nuts until they're about 100 years old"), via strawberry gum, lilly pillies, native lemongrass and wild rosella.
While the Chans are fascinated by the bunya bunya (from the tree's coexistence with dinosaurs to its reputation for shedding deadly nuts on unsuspecting heads), they don't think the pumpkin-like flavour of bunya nuts will work in chocolate.
"What's really amazing is the strawberry gum," says Fanny. "It's like strawberry and mint at the same time."
Tasmanian mountain pepper-berry leaves, meanwhile, are "almost like five spice", says Alex. "What's funny about the indigenous ingredients is that they're not mono-flavoured; there's always something that surprises you."
Fanny says the heat is more delayed, comparing the leaves to the pepper berries she uses in her praline. She chews on the leaf and coughs when its fiery punch finally detonates.
Alex passes her a bag of Indigiearth's tiny, shrivelled bush tomatoes - mini powerhouses of flavour. "This is like Chinese medicine," he laughs. "It's so intense."
"It's bitter," says Fanny. "It needs something sweet with it, like strawberry or raspberry."
Indigiearth's native lemongrass, meanwhile, intrigues Fanny. "It's like galangal," she says. "It'd go well with coconut milk in a praline."
The siblings plot other possibilities: using jam-friendly quandong to create a jelly to place inside a marshmallow, filling an Easter egg with lemon myrtle cream or adding pepper-berry leaf to a choc-orange peel.
After a few days with these ingredients, Fanny produces a praline with native river mint and, unlike conventional mint in confectionery, which can have the nose-clearing intensity of mouthwash, the indigenous version has a smooth elegance that goes well with the dark chocolate. She's still experimenting with wattleseed coffee brittle - will crunchy cocoa nibs underscore the earthy wattleseed flavours or overwhelm them? - and sprinkling strawberry gum on slabs of strawberry and raspberry-encrusted white chocolate. The gum's clean finish is a reset button for all that sweetness.
It took Fanny a year to create a caramel brittle that didn't trap teeth in involuntary chew-a-thons, so it's early days for these experiments. But she's excited about these prototypes and upcoming concepts - lemon myrtle clusters in particular.
"You'll never find this anywhere in Europe," says Alex.