Try what my smart little hillbilly Grandma used to do.
After she would peel an onion (any member of this family
would do) she would take the root out and plant it again in
the garden. She called them the "forever plant" and with one
onion/garlic/leek/etc, she could have a steady supply for
many years. I believe that she also planted a lot of other under
ground veggies, best try them your selves.