This is a sweet drink, given extra kick by spicy nutmeg.
First separate the seeds from the pulp of the passion fruit. Spoon out the contents of the passion fruit into the blender and pulse until the seeds are slightly loosened from their thick juice. Remove from the blender and set in a sieve over a bowl. Rub with a spoon in a circular motion, until the seeds are almost dry and the juice has collected beneath.
Place this juice and all the other ingredients except the nutmeg in the blender and whizz until smooth. Serve in a tall glass, with a dusting of nutmeg on top.