Preheat oven to 200C. Turn on ice cream machine to chill.
For the Kaffir Lime and Lemongrass Ice Cream, combine the milk, cream, kaffir lime leaf, kaffir lime zest and lemongrass in a medium saucepan over medium heat and bring to just below boiling point.
Meanwhile, whisk the egg yolks and palm sugar together in a medium bowl until pale.
When the cream and milk mixture has reached just below boiling point, remove from the heat. While whisking continuously, pour approximately half of the mixture over the egg yolk mixture, whisking until combined.
Add the remaining cream and milk mixture and continue to whisk until fully combined. Return mixture to the saucepan and cook over medium heat, stirring continuously, until the mixture reaches 80C.
Remove from the heat. Strain the mixture into a cool metal bowl and set over the ice bath to cool completely. Transfer the mixture to the ice cream machine and churn until set. Once set, transfer to the freezer until needed.
For the Roasted Pineapple, line a baking tray with baking paper. Spread the pineapple cubes onto the lined baking tray. Place into the oven to roast until charred and golden, about 30 minutes.
For the Roti, combine the flour, salt and 125ml water in the bowl of a stand mixer fitted with a dough hook. Mix on medium-high speed until a dough forms that is very soft and stretchy, about 3 minutes.
Fill a medium sized bowl with vegetable oil.
Lightly flour hands and pull the dough out of the mixer. Separate the dough into 4 portions and squash into disc shapes. Add the discs of dough to the bowl filled with oil, ensuring the discs are fully submerged then set aside to rest for 30 minutes.
Oil a clean bench space.
Remove a disc of dough from the oil. Place the disc on the bench and lightly stretch the dough outwards by starting in the middle and pressing gently outwards with the palm of your hand. Use fingertips to pick up the edges of dough and place back down, stretching slightly larger each time. Stretch the dough until it is thin enough to be transparent. Avoid large holes, however, smaller holes are not detrimental and will add to the flakiness of the roti.
Spread 20g of the butter in the centre of the roti and then fold the edges in, similar to an envelope.
Heat a large frying pan over high heat and add 1 tablespoon of oil. When the oil is hot, add the roti and cook until golden brown, about 1-2 minutes. Flip the roti over and cook until golden brown on the other side then remove from the heat and sprinkle with salt.
Clap your hands around the roti about 3 times until becomes a flaky, crispy ball. Set aside until needed for plating. Repeat this process with the remaining dough discs, wiping out the frypan in between each roti if necessary.
For the Palm Sugar Chilli Caramel, combine the sugar and palm sugar in a small bowl. Sprinkle the sugar mixture, in an even layer, onto the base of a medium saucepan. Cook over medium heat, gently swirling the saucepan, until the sugar has melted and turns golden brown in colour.
Reduce the heat to low and whisk in the warmed cream until fully combined. Whisk in the butter, one cube at a time, until combined. Stir in the chilli and salt. Transfer to a serving jug and keep warm for serving.
For the Kaffir Lime and Nutmeg Sugar, combine ingredients in a small bowl and set aside.
To serve, sprinkle the Roti with Kaffir Lime and Nutmeg Sugar and place onto serving plates. Top with Roasted Pineapple pieces. Add a scoop of Kaffir Lime and Lemongrass Ice Cream to the side of the Roti. Drizzle the Palm Sugar Chilli Caramel generously over the dish and serve.