Method

Preheat the oven to 190°C fan-forced (210°C conventional). Grease and line a swiss roll tin or large rectangular baking tin (approx. 33x23cm) with baking paper. 

First infuse the milk for the custard. Place the coconut milk and shredded kaffir lime leaves in a medium saucepan over medium heat. Slowly heat until just starting to bubble, then remove from the heat and set aside for 30 minutes to infuse as you make the meringue.

For the meringue roulade, place the egg whites in a clean large bowl. Using an electric hand or stand mixer, beat the egg whites on high speed until they form soft peaks. While beating continuously, gradually add the caster sugar, 1 tbsp at a time, followed by the brown sugar. Once all the sugar has been added, continue beating for a further 5 minutes to form a beautifully stiff, thick, and glossy meringue. In a small cup, whisk together the vinegar and cornflour and add to the meringue, beating on medium speed until well-combined. Add the chopped mint and beat again on medium speed until folded through. Spoon the meringue into the prepared tin and gently spread out with the back of a spoon to form an even layer, being careful not to deflate the meringue. Place in the preheated oven and immediately lower the oven temperature to 170°C fan-forced (190°C conventional). Bake for 10 minutes, then reduce the temperature again to 140°C fan-forced (160°C conventional) and bake for a further 15 minutes. The meringue will have puffed up and have a crusty surface. Remove from the oven and leave to cool for 5 minutes to allow the meringue to deflate a little. Place a piece of baking paper just larger than the size of the meringue on your work surface, long side facing towards you. Working quickly and carefully, invert the meringue onto the baking paper and carefully peel off the baking paper from the base of the meringue. Leave to cool completely at room temperature.

As the meringue bakes, make the custard. Remove the lime leaves from the milk you prepared earlier, squeezing out any excess milk from them, and return the saucepan over medium heat, slowly bringing the infused milk to the boil. In a large bowl, whisk together the egg yolks, vanilla paste, and caster sugar until pale, then whisk in the cornflour until smooth. Once the milk is just starting to bubble, remove from the heat and gradually pour the hot milk into the egg mixture, one third at a time, whisking together until smooth. Return the mixture to the saucepan, place over medium heat and cook, whisking regularly, until the mixture boils and thickens to form a smooth, really thick custard. Place a layer of cling film over a baking tray, pour over the warm custard, and cover the surface with cling film to prevent a skin forming. Place in the freezer for 20 minutes to cool and set.

For the strawberries, place the chopped kaffir lime leaves and caster sugar in a mortar and pestle. Grind for a couple of minutes until the leaves turn the sugar a vibrant green, then pass through a sieve to remove the leaves. Place the chopped strawberries in a large bowl, add the kaffir lime sugar, lime juice and chopped mint leaves, tossing to coat. Set aside for 10 minutes to allow the flavours to mingle.

To finish the custard, place the cream in a bowl and using an electric hand mixer, beat until soft peaks are reached. Remove the chilled, thick custard from the freezer, transfer to a bowl, and whisk vigorously until smooth. Fold the whipped cream into the custard.

To roll the roulade, spread two-thirds of the custard evenly over the surface of the cooled meringue, leaving a 2cm border on the long edge furthest away from you without custard (as the custard will spill onto this as you roll the meringue). Layer two-thirds of the strawberries over the top of the custard. With the long edge facing you, roll up the meringue tightly, using the baking paper to help you and gently removing this as you go, to form a log. Carefully transfer the roulade, seam side down, to a serving platter/board. Spoon the remaining custard down the length of the roulade, and top with the remaining strawberries and any macerating liquid. To finish, top with a few extra mint leaves for decoration. Slice and serve. This is best eaten on the day, but will keep well refrigerated for up to two days.