300ml skimmed milk
2 level tbsp sweetener granules
Finely grated zest of 2 limes, plus juice to taste
3 small sheets of leaf gelatine
300g fat-free natural Greek-style yogurt
Kiwi fruit, peeled and roughly chopped, to serve
Seedless green grapes, halved, to serve
1 Put the milk, sweetener and most of the lime zest into a saucepan over a low heat and stir until the sweetener has dissolved.
2 Meanwhile, soak the gelatine sheets in a large bowl of cold water for 5 minutes. Squeeze out the water from the softened gelatine and add the gelatine to the milk in the saucepan. Stir gently until dissolved. Remove from the heat, leave to cool and stir in the yogurt. (Strain out the zest if you don’t want any ‘bits’ in your dessert.)
3 Divide the panna cotta mixture between 4 small moulds or ramekins. Chill for at least 3 hours, or until set.
4 Briefly dip the base of each mould or ramekin in hot water and turn out the panna cottas on to plates. Sprinkle over the remaining lime zest. Serve with kiwi fruit and grapes tossed with lime juice to taste.