Lightly oil 6 x ½-cup-capacity moulds (dariole moulds are good here).
Place the Puhoi Valley Spiced 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 Spiced 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.