Where can I find preserved lemons in London?

In the houses of parliament. Seriously though, all of the supermarkets should stock what you’re looking for i’d imagine.

If you can’t find them in a small store, I would try Harrod’s Food Halls or Fortnum and Mason’s.

They’re a Moroccan specialty, so I’m sure you could find them in the shops in “Little Morocco”, Golborne Road.

Any larger supermarket should have them. My local Waitrose or Sainsburys both stock them.