These are just like the salt preserved lemons, but in a smaller jar.
Apparently they discolour round the edges when you preserve them in salt.
I don’t even know if this is the right way to preserve limes.
I seem to remember that Nigella Lawson freezes them first to help them break down in the salt and juice, but her book is like, 100 miles away and I couldn’t find the recipe online.
Oh well. 😉