Lightly oil 6 x ½-cup-capacity moulds (dariole moulds are good here).
Place the Puhoi Valley Caramel & White Chocolate Milk, cream, caster sugar, vanilla bean and lemon zest in a saucepan over low heat. Bring up to a simmer (watching it does not boil), and stir to dissolve the sugar. Remove from the heat and set aside.
Place the water in a small ramekin and sprinkle over the gelatin. Leave until a sponge is formed. Dissolve the gelatin by placing the ramekin in a saucepan containing a small amount of very gently simmering water.
Stir dissolved gelatin into the Puhoi Valley Caramel & White Chocolate Milk mixture. Remove vanilla bean and stir in the yoghurt.
Pour mixture into the moulds, cover and chill for 4 hours or overnight
To serve, bring panna cottas back to room temperature (so they are lovely and wobbly). Unmould by dipping moulds briefly into warm water. Invert each into a shallow bowl and serve with seasonal fruit.