- Step 1
Grease a 5cm-deep, 18cm (base measurement) fluted tart tin. Process the pretzels and biscuits in a food processor until finely crushed. Add the brown sugar and butter and process until well combined. Spoon the biscuit mixture into the prepared tin and press evenly over the base and side. Place in the freezer for 15 minutes to set.
- Step 2
Meanwhile, for the ice-cream, combine the cream, milk and condensed milk in a large saucepan over medium heat. Bring to a simmer. Use electric beaters to whisk the egg yolks and sugar in a bowl until very pale and thick. Add the lime rind and juice. While lightly whisking, gradually add the hot cream mixture in a thin, steady stream. Return to a clean saucepan over medium-low heat. Cook, stirring constantly, for 10 minutes or until mixture thickens slightly and coats the back of a wooden spoon (be careful not to overcook as the custard may curdle). Set aside to cool.
- Step 3
Stir in the tequila, Grand Marnier and a little green food colouring. Strain into an ice-cream machine and churn following manufacturer’s instructions. Spoon the margarita ice-cream over the biscuit base and place in the freezer for 8 hours to set.
- Step 4
Meanwhile, line a baking tray with baking paper. Use a spatula to thinly spread the chocolate over prepared tray. Top with a few drops of green food colouring. Use a skewer to create a swirled effect. Set aside to set. Break into shards.
- Step 5
Process the caster sugar, lime rind and a few drops of green food colouring in a food processor until well combined.
- Step 6
Remove ice-cream pie from the tin and place on a serving plate. Top with the chocolate shards and sprinkle with the lime sugar.