Anything you want to know about them, please read Jane Grigson's chapter on them in her ineffable, The Fruit Book. Her prose is educational & poetic.
But nothing beats eating these mysterious green fruits! Honey, syrupy summer, sweet, meaty. And tiny enough to pop the whole thing in your mouth at once.
Roast them to keep the colour & if jamming keep the flame really low. Cook too far and you'll lose the colour.
I found all this fruit at my local, the Newington Green
greengrocer. I feel ecstatically lucky because London neighborhood shops aren't famous for having fresh fruit, especially seasonal & local British grown fruit & veg.
Party Tomatoes are not a real name. They were renamed by Melanie, my First Assistant, when we worked together at Citizen Cake. They are striped (pronounced with 2 syllables) and also green. I love them muchly and will eat them out of hand, maybe garnished with a pinch of salt, as much as I can in summer.