It may still be hard to find in the supermarket, but home growers are going crazy for oca (or oka, or ocha, or New Zealand yam).

Oca has a slight lemony potato flavour, and can be eaten raw or cooked. Some varieties that are so sweet that they are eaten as fruit. Even the leaves can be eaten as greens.

Their best feature: they are extremely easy to grow home. They don't suffer all the diseased potatoes do, they can grow in very poor soils, and light doesn't ruin them, just makes them sweeter.