Put the gelatin sheets in cold water to soften them. Pour the coconut milk into a saucepan, add the sugar (200 g) and heat, stirring with a wooden spoon, until the sugar melts.
Drain the gelatin leaves. Incorporate them into the mixture while stirring. As soon as they are melted, remove the pan from the heat. Leave to cool, then refrigerate until the mixture begins to set slightly.
Pour the cream into a terrine and whip it into whipped cream. Add it to the coconut milk mixture. Pour the mixture into a soufflé or springform pan and leave it in the freezer for 2 hours. One hour before serving, remove it from the freezer to chill in the refrigerator.
Prepare the sauce. Pour the coconut milk (20 cl) into a saucepan, add the chocolate cut into pieces or coarsely grated and melt it over very low heat while stirring. Once the chocolate has melted, add the rum and mix. Remove from heat and pour into a sauce boat.
Just before serving, unmold the cake onto a serving dish, sprinkle with grated coconut and serve immediately, accompanied by the white chocolate sauce and surrounded by slices of lime for decoration.
