I came across what could be a great Science project, while visiting Pinterest, a couple weeks ago. Super easy to do and since I had the roots already there was no need to buy more.
Place the roots from green onions in a glass of water
After a week they were ready to be cut
Since these grow so fast (every week will need to be cut) you can place them in an empty water bottle in place in the freezer. When you cook with them, just shake out what is needed.
Both Ideas came from Pinterest.
This post is linked to Science Sunday