Mulberry leaves (not technically a weed but I've never used the leaves before)
Although the kids weren't that impressed with the idea when I told them we were having weed soup for dinner!
Actually I'd been sneaking weeds into our meals for weeks :)
So my soup did contain a couple of potatoes and some carrots but also heaps of weed. And in the end te kids agreed that eating weeds wasn't that bad after all.