We had a grapefruit that needed using, and S has started liking chamomile (when did that stop being chalomile? Is it just inside my head that it was ever chalomile?) tea, but tea can be a bit much in this weather, so I suggested grantia. Granita is probably the simplest frozen dessert imaginable, unless you're in the habit of filling ice cube trays with OJ; it's frozen juice, just broken up a bit. So I made a litre of chamomile tea, got all the flesh out of the grapefruit, cut most of the zest away from the pith (slicing finger in the process), boiled up the well-steeped tea with the flesh and zest and about 75g sugar (dissolve sugar, bring to boil then boil for 2 mins), strained the lot and after cooling naturally, froze the results. You're supposed to break it up with a fork every half hour, but I forgot; no matter, breaking it up when you remember is fine, and if you really forget just tip the whole lot into a blender and blitz it. Results taste awesome and look like this:
I imagine that any citrus and aromatic tea - not ordinary black tea, though, the tannins could be too much for most citrus - would work quite well. If summer continues in a similar fashion expect further experimentation.