Green Amaranth aka Rajgira, grow for it's greens or for it's small nutty flavoured seeds to be consumed as a calcium rich cereal.
 
It will readily self seed and proliferate your garden! 
It grows well in pots too. Grow it year around to enjoy all the goodness.
 
All the seeds by TOG are handpicked and are heirloom, you can keep collecting the seeds and keep growing!