All the supermarkets seems to sell the same brands and I have no idea if any of them are mostly processed in Europe or elsewhere in the world.
Do you have recommendations? I like the ones with a fruity taste more.
This one is my current favorite:
Click to view
They claim on the package that they care about sustainability, better working conditions and social engagement.
Though it’s not (currently) done on a large commercial scale, you can absolutely grow tea plants in the UK.
There’s a few small companies doing it, who normally produce fairly expensive stuff, but also you can grow the plant (Camellia sinensis) yourself in most areas of the UK in a pot in the garden.