High in Iron, vitamins & natural histamine, apparently, Rap! Although I would have thought sand would have been much simpler for the ninja...

Rædwulf's Nettle soup (loosely adapted from others, but mostly Hugh Fearnley-Whittingstall & Lindsay Bareham)

Serves a reasonably hungry 1

As many nettles/nettle tops as suits (about a loosely (lob in a bucket & don't trouble to squash) quart fresh).
An onion, chopped
A stick of celery, chopped
Vegetable/chicken stock
Generous pinch of nutmeg
Thyme
Butter

Soften the onion in the butter. Add the stock, nettles, celery & nutmeg. Simmer till done. Liquidize. How simple did you want? :)

You can add anything else you please, of course (my usual method of cooking - "I've got that, that, & that... OK..."). I've seen specific mentions for carrots, rice & spring onions, but mine don't last, I'm tellin' yer... :)