I don’t know why it hasn’t occurred to me before, that green onions (also known as spring onions, green shallots, onion sticks, scallions, long onions, salad onions, syboes, baby onions, precious onions, or yard onions) are just like any other bulb that you would plant in the garden. And similarly they re-grow each year. I read about someone re-growing their green onions after using them in cooking and a I had ‘mind-blown’ moment when it became so obvious.
The technique is pretty simple. Take your green onions, cut off the green stalks from the bulb leaving about an inch of the bulb. Put the bulbs in a small glass with just enough water to cover the bottom of the bulb. Leave somewhere sunny for about 10days, changing the water regularly. Cut off the green shoots and repeat.
Voilà! free food. Obviously you will need a few glasses running at a time to ensure a plentiful supply for the kitchen.