Ooh, interesting on the yuzu. M&S have started selling yuzu flavoured sparkling water and I think I knew it was a type of citrus, but I didn't know it would grow in the UK, although I would question whether that would be anywhere, or just the drier sunnier regions.
I live in the epicentre of the rhubarb triangle, so called because our particularly cold, wet climate is perfect for growing rhubarb. Therefore if yuzu is expecting Brighton or Norfolk, it might not be quite so successful.
I still find this all very strange. Most of these 'middle class' foods really are very inexpensive. You could set yourself up for months worth of tasty affordable spiced food for under a tenner with a few 100 g packs of Asian branded spices which cost about 70 p each in most supermarkets, along with cubes of frozen garlic and ginger, which is far cheaper than fresh. Plus its not like the knowledge is hard to come by, you can't move for cookery shows and recipes on the internet. Just about anyone could learn if they wanted to.
I'm as working class as they come btw, so I speak from experience of learning about all the 'new' foods and ingredients that have become everyday over the last few decades.