I was very surprised to read that potato leaves are edible. But I realised that you're referring to what we call sweet potato in the UK.
Here, our potato leaves look very different...

In fact, they are a totally different plant. And the leaves of what we call potatoes are poisonous!
However, I've seen on Google that sweet potato leaves can be eaten in a similar way to spinach. So soup is a great idea. In fact, I want to get some sweet potato leaves to try. Because I eat a lot of spinach.
Thanks for your post, which prompted me to learn more about different types of potato.
!BBH
RE: Important use of Vegetative Potatoes leaves.