I have a patch of purple-skinned walking onions in a sunny, dry area of the yard. Walking onions are a perennial that produces small onions on the top of its stems. Both the onions on the stems and the onions growing in the ground are edible, and have a stronger flavor than normal onions. The onion greens get fibrous quickly once an onion is growing on the end of the stem, so you have to either get the greens early on or reserve them for simmering in stocks and broths.
This is the first year the onions are established enough for a full harvest, as last year, I had just recently started them and replanted most of the onions from the harvest. These onions are now in many of the dinners I cook. They do not add bulk to the meal, but they have a great onion flavor.
Here are some photos from before the onions were ready to eat. I think that here, they look like aliens or sea creatures!