Vanilla Buttermilk Panna Cotta with Summer Fruits

For the Panna cotta
2 teaspoons powdered gelatine
100ml / 3 1/2 fl oz cream (whipping)
55g / 2 oz caster sugar
1/2 vanilla bean, split lengthways
250ml / 9 fl oz buttermilk
150g / 5 1/2 oz low-fat Greek-style yoghurt

2 passion fruit
2 teaspoons caster sugar
1/2 small pineapple, peeled and cored
1/2 small red papaya, seeded and peeled

To make the panna cotta, lightly grease 4 x 125ml /4 fl oz metal, glass or ceramic moulds.

Put 2 teaspoons of water in a small bowl and sprinkle with the gelatine. Leave the gelatine to sponge and swell. Put the cream, sugar and vanilla bean in a small saucepan and stir over low heat for 2-3 minutes, or until the sugar has dissolved.

Whisk the gelatine mixture into the cream mixture until the gelatine has dissolved. Set aside to infuse for 3 minutes.

Scrape the seeds from the vanilla bean into the cream mixture, discarding the vanilla pod. Pour the mixture into a bowl. Shake the buttermilk carton well before measuring, then whisk the buttermilk and yoghurt into the cream mixture. Divide the mixture among the prepared moulds. Put the moulds on a tray, cover with plastic wrap and refrigerate for 3-4 hours, or until set.

Sieve the passion fruit pulp into a small bowl, discarding the seeds. Stir in the sugar. Cut the pineapple and papaya into long thin slivers.

To serve, gently run a small knife around the side of each mould and turn the panna cotta out onto large serving plates. If they don't readily come out, briefly dip the moulds in a bowl of hot water. Arrange the fruit slivers around the panna cotta and drizzle with the passion fruit juice.