- Step 1
Line the base and 2 long sides of a 6cm-deep, 24cm x 12cm (8-cup) loaf pan with baking paper, allowing sides to overhang. Spread the pistachios over a foil-lined heatproof tray, keeping them close together. Stir the sugar and water in a small saucepan over low heat until sugar dissolves. Increase heat to medium and bring to the boil. Cook, without stirring, for 10 mins, or until golden brown. Let the bubbles subside, then pour over the pistachios and set aside for 20 mins or until cold and set hard.
- Step 2
Place the eggs, egg yolks and extra sugar in a heatproof bowl over a saucepan of simmering water (don’t let the base of the bowl touch the water). Use an electric beater to beat for 5 mins or until very pale, thick and increased in volume. Remove the bowl from the pan and beat in the vanilla and chocolate until combined.
- Step 3
Fold the whipped cream and praline into the egg mixture until evenly combined. Transfer to the prepared loaf pan and cover the surface with plastic wrap. Freeze overnight or until firm.
- Step 4
Remove semifreddo from the freezer and peel off plastic wrap. Use a non-serrated knife to loosen both ends, then turn out onto a chilled platter. Remove the baking paper and return semifreddo to the freezer for 30 mins or until firm.
- Step 5
Break the praline into pieces and process in a food processor until coarsely ground.
- Step 6
Just before serving, arrange sliced mango on top and sprinkle with chopped pistachios.