Here people use it as food, it has a spinach like taste, but it is better to be cooked.
I like it for several reasons, it has really deep tap root, I cant find information how deep it is, but once I was digging for a pond and I got at 1,5m and the root of that plant was still going down(I am pretty sure it was going down much deeper), and it belonged to a plant that was not that big at all.
During summer(we have really dry summer here), it is one of the few plants that continue to look green and happy even after 2-3 months without any rain, the only similar plants that manage this I can think of now is the alfalfa and the horseradish. For a climate with a similar type of summer I cant think of any better plant that gives you green leafs.
It tolerates shading, and will thrive in clay soil, you can cut it several times during the year and it still keep showing again and again, if you let it to develop seeds and the seeds mature it will calm down eventually.
^ I see it really often here on places where other plants just cant manage to grow good, maybe thats why I like it so much, that plant is a really good fighter.
How people prepare it sometimes: