Boil the beetroot until tender, 30–45 minutes depending on size. (If they’re really large, they can take up to an hour or more. Drain and leave until cool enough to handle, then rub off the skins (they should come away easily). Boil the potatoes for 12–15 minutes, until tender. Drain and leave to cool.
Chop the beetroot and potatoes into bite-sized pieces. Put in a large bowl and add th