Sorry Eagle, I thought I was posting a new message! Cheers.
I was just told about this kind of 'Spinach' today. I'm not allowed to order any seeds because the we're not able to eat all of the New Zealand spinach I'm growing, but this Malabar Spinach is making me think in terms of Food Forest. http://www.thekitchn.com/what-is-malabar-spinach-91477 'Some say' it is very invasive! :)