Well done to ladyredspecs, chef mimi and Alice at Nom Nom Cat for getting this one right – the third mystery ingredient is indeed a rambutan! Also known as a “hairy lychee”, the name is apparently derived from the Indonesian word rambut meaning “hair”.
I had never heard of these before I saw them in the supermarket this weekend, and had to open one as soon as I got home to have a bit of a taste! Very similar to lychees, but I think a bit sweeter and less juicy.
At this point I usually write up a recipe using said mystery ingredient, but on this occasion having had a browse for inspiration over the internet I think it would be a bit of a waste to mix them with anything else….and I thoroughly enjoyed munching my way through the lot!
applepiezucchini 
Yes, I agree, best eaten fresh and unadorned
Never liked them as a kid – they tasted too much like rose petals.