Tales of the ‘caviar of the East’ reach my ears within an hour of landing in Kota Kinabalu — the capital of Sabah state, Borneo. For more than 1,000 years, its aphrodisiac and potent health powers have driven men to the limits of bravery in order to attain it. The Chinese call it Yan Wo — bird saliva. One of the world’s most expensive delicacies, one kilogram can cost up to US$10,000. Deep in the darkness of Borneo’s Gomantong and Niah limestone caves is where the wizardry happens. Male swiftlets find the perfect nook on the vertical 180ft-high walls and begin to build their nests. But no mere bundle of twigs will do in such extreme conditions. Instead, the little black bird excretes saliva from under its tongue and binds loose feathers together to form a live cement. This is what the Chinese and Malaysians hanker for, and they pay top dollar to have the saliva strands painstakingly separated from the feathers with tweezers and mixed into the life-prolonging bird’s nest soup that can cost US$110 per bowlful.

So local men rig up treacherous networks of ladders strung together to reach the cave’s high ceilings. One slip could mean death. At the top, they gently dislodge the nests and lower them down in a roped basket to a friend or family member waiting on the guano-splattered floor below. It’s a skill passed down through generations and highly respected. I had to see if could find some… My partner and I start the search amid the twinkling lights of a pasar malam (night market) on Kota Kinabalu’s waterfront. Faces appear from behind thick clouds of wood-fire smoke proffering piles of lobster, prawns, large fish, small fish and just-the-right-size fish laid out on sheets of newspaper. With no sign of the bird’s-nest soup, we pick out a middling size fish and seat ourselves at one of the long trestle tables. A pot of finely sliced chilli sits on the plastic tablecloth. I follow the lead of the locals, pile it on, and take a bite.

“Another coconut, please!” I stammer, taking great soothing gulps. The next night we try another, less touristy, fish market on Sedco Square. A couple we met in the hostel, Sarah and David, decide to assist in the hunt. Here, beneath neon strip lights, the fish swim in tanks positioned around a gaggle of plastic tables and chairs. It’s like a trip to the aquarium; the glass cubes before us house all manner of fish, while one containing giant sea snails particularly catches my eye. Tiny elderly ladies fillet fish with a swish of a cleaver, and above the stall fronts hang hulking great coconut crabs, strung up by their waists like Mission Impossible-style ninjas.

The only other tourist, a beefy Australian bloke, sits at a table with the shell of a horseshoe crab — a crustacean that appears to have pilfered the armoured plates of anarmadillo — balanced upside down before him. It’s among the most expensive seafood you can try. “Tasty?” we ask him. He rubs his belly and blows out his cheeks. “Kinda,” he shrugs. We opt for soft-shell crabs, garlic squidand ginger-spiced snapper.

Sarah wanders off to find a toilet and returns with a big grin. “Look what I’ve found!” she shrieks, placing a sealed plastic beaker in the centre of the table. I scan the cartoonish label of reds, blues and yellows. In the top corner, inside a star-shaped speech bubble ate the words: Bird Saliva. I peel back the lid and sniff at the pale glue-like substance inside. There’s not much to go on. So I pour a dollop onto my tongue. I swill it around my mouth and everyone at the table leans forward in a collective “how does it taste?” It’s slightly sweet, but the gelatinous strings of saliva get stuck between my teeth. An acquired taste, definitely. But then perhaps it’s right that consuming one of the world’s most expensive delicacies is something I’ll only do once.