I find that when I buy green onions that most of it goes bad before I can use it all. The last time I got some I decided to try to dehydrate them in my oven. I sliced all of the green onions up, chopping the white parts in half to help them seperate. I put them on my silcone mat on a cookie sheet turned my oven on warm (170) and left to door slightly ajar to try to get the temp down to 150 or so. Check on them after a while and stir with a spatula. When dried I stored them in a ziploc bag in the spice cabinet. This is what works for me now for more ideas go check out Rock in my Dryer.