We use Scallions in eggs, mashed potatoes and randomly for seasoning. It wasn't until recently while browsing Pinterest that I came across a pin indicating that if you put your scallions in water after using most of the green onion portion, they will sprout!
As you can see, it totally works! I literally chopped my scallions down to about an inch or two of green, put them in a little jar with water, left them on my windowsill in my kitchen and walla, sprouts started within days!!
Anyone know of any other plants I can do this with?