I always buy green onions, use two, and the rest wilt in the fridge until I throw them away.

But then I discovered this trick:

Just use the tops of the green onions, plunk the rest into a jar, add some water and put in the sun.  They re-grow!  I’ve only used these twice now, and they keep springing back.  Eventually, I imagine I’ll use them all up and get some new ones, but in the meantime this works pretty well.