In a big mixing bowl whisk the egg yolks, cornflour and sugar together until pale and creamy. Heat the coconut milk in a pan, taking it off the heat just before it boils. Whisk the hot coconut milk into the egg yolk mixture, return to the pan on a low heat and whisk for a couple of minutes until it has thickened slightly. Allow the mixture to cool.
Put the cream into a mixing bowl and whip until peaks form. Fold in the coconut milk mixture. If you have an ice cream maker, put the mixture in and churn. If not, transfer it to a chilled metal container and freeze for 2 hours, then whisk to break down the ice crystals. Put the mixture back into the freezer in the chilled container and repeat the process again after 2 hours.
To make the pistachio praline, scatter the pistachios in the centre of a greased baking tray. Put the sugar into a heavy-based pan with
Finely grate the nutmeg and lime zest on to a tray. Scatter the praline dust alongside, then pop the ice cream on the tray and take it to the table. Get everyone to drop their scoops of ice cream into the lime and nutmeg mixture, then repeat with the praline. Top each bowl of ice cream with a sprinkling of coconut.