Green onions are an extremely useful, versatile allium. If you like to cook with green onions but are worried about running out, you can keep the white ends in a glass of water where they will regrow into new, delicious onions.
Just put the root ends in a glass of water and put that glass in a sunny window, and change the water about once a week. After five days or so you should be able to begin harvesting the green ends of the onions, depending on how much green you started with. Just snip what you need for your dish—you can take up to 70% of the green, leaving the rest behind to keep growing.
This article was originally published in 2012 and updated on 3/24/2020 by Claire Lower. Updates include the following: Updated formatting to reflect current style, changed feature image, revised first and second paragraph.