Scoop out the pulp and seeds from the passionfruit and whizz this up in a food processor, blender or smoothie maker to separate the seeds from the pulp.
Strain this through a sieve to remove the seeds and either discard this or keep a few back if you want seeds in your curd.
In a bowl, whisk the egg, yolk and sugar together until smooth.
Stir in the sieved passionfruit juice to the egg mixture until combined.
Melt the butter in a saucepan on a low-medium heat and slowly add the egg mixture whilst stirring.
Stir continuously for roughly 10mins until the curd has thickened to a thin custard consistency and coats the back of your spoon/spatula. Pour this into a jar and allow it to cool on the side before refrigerating.
Notes
Makes roughly 270ml of curd, which is roughly one jam-jar full. If you're planning to make more as gifts, scale up as needed.