I once did the catering for a free festival in Bath, in the '70s. The local health food shop (Harvest) donated a huge sack of muesli which we mixed with water and handed out for free on paper plates. That was the only food available.
I have a few favorites at glasto: the Indian takeaway by the stone bridge, the fre food at the Hare Krishna tent and what I think was called Pauline Fowler, Home of the Growler.
I haven't been for a few years and interested in whats on offer. ✌️