What besides green onions or scallions can you put in a jar of water and have them grow for you?

Thanks!
I meant grow so you can eat them. The green onions you just snipe off the top and eat them.
Sprouts were a good idea!

Where do scallions grow?

I like to use local produce whenever possible. Most of the items at our local green market are high quality but the scallions are not as nice as the ones at the supermarket– is this because scallions don’t grow well locally (In New York) ?
Where do most scallions come from?

If you plant a fully mature green onion, can you actually grow more onions?

Ok, so my mom put an old onion in a plastic bag, and sealed it, and put it in the fridge. After a few weeks, we checked on it, and it actually grew scallions!!!!!
So she’s wondering: If we actually plant a whole green onion (in soil, not a plastic bag), will it actually cause it [...]

Is it possible to grow scallions using the scallions I bought at the grocery store?