For the Coconut Purée, split a coconut in half over a large bowl and reserve the coconut water.
Note: If you would like to serve this dish in half a coconut shell as Samuel did, repeat this process with a second coconut, the flesh and water from the second coconut is not required in this recipe therefore can be used elsewhere if desired.
Use a coconut shaver to remove the flesh from the coconut halves and place into a blender with the reserved coconut water. Blitz on high speed to a smooth purée. Transfer the purée into a fine sieve lined with muslin cloth, squeezing gently to remove the excess liquid. Discard the excess liquid.
Reserve 3 tablespoons of the purée in a small bowl for later use marinating the fish. Set the remaining purée aside in a bowl until needed for the Red Curry Custard.
For the Red Curry Paste, combine all ingredients in a mortar and pestle and grind to a smooth paste.
For the Red Curry Custard, heat a medium frypan over medium heat, add the rice bran oil then add the Red Curry Paste and fry, stirring, until fragrant, about 5-8 minutes.
Reduce the heat to low and add the reserved strained Coconut Purée in a bowl. Simmer for 6-7 minutes, strain through a sieve lined with muslin cloth into a clean bowl and set aside to cool slightly.
Half fill a large wok with water then place over medium heat and bring to a simmer.
Combine the eggs and extra egg yolks in a medium bowl and whisk gently until combined, careful not to create too many bubbles on the surface.
Whilst whisking continuously, slowly add the cooled curry base to the egg mix, whisking until combined.
Pour the liquid into 4 x coconut shell halves or 4 x 125ml capacity ramekins. Place into a large bamboo steamer basket and cover with the lid. Place the bamboo steamer basket over the wok of simmering water and steam until set, about 8-9 minutes.
Remove from the steamer and set aside to cool. Top up the water in the wok and reserve the wok and the steamer basket off the heat for later use.
For the Tamarind Barramundi, place the tamarind purée and 500ml of water into a small saucepan over low heat and bring to a simmer, then continue to simmer for 15 minutes. Strain the liquid through a fine sieve. Place 3 tablespoons of the strained liquid in a shallow, medium sized bowl then add palm sugar, chilli and reserved coconut purée and mix well until combined. Set the marinade aside until needed.
Remove the skin from the barramundi fillets and set the skin aside until needed. Cut the fillets in half, lengthways, then in half, widthways, to create 16 by 10cm x 2cm batons. Add the pieces of fish to the bowl of marinade. Toss to coat the fish in the marinade, then place a portion of the fish onto a beetle leaf and roll the leaf up to enclose the fish like a parcel. Repeat this process with the remaining pieces of fish.
Place the wok back over medium heat.
Lay the betel leaf parcels into the bamboo steamer basket and cover with the lid. Cook until the fish is almost cooked through, about 4 minutes.
Heat oil in a deep frypan to 180C.
Season barramundi skins with salt and slice into thin strips. Add skins to the hot oil and fry until crispy, about 1 minute. Remove from the oil and place onto paper towel to drain. Season with salt and set aside until needed.
To serve, arrange 4 parcels of Tamarind Barramundi in Betel Leaf on one side of each serving plate. Place a coconut half or ramekin of Red Curry Custard next to the parcels of fish. Top the Red Curry Custard with some crispy fish skin and sliced red chilli.