Gently stir through the passion fruit flesh. For the lemon curd, put the lemon zest, lemon juice, sugar and butter in a heatproof bowl. Sit the bowl over a pan of gently simmering water ...
Remove the lemon curd from the heat and set aside to cool, stirring occasionally as it cools. Once cooled, spoon the lemon curd into sterilised jars and seal. Keep in the fridge until ready to use.