A simple hook that attaches to an Ikea Bror shelf - (link)
When you buy the shelf you get 3 additions screws (for extending the shelf I guess), you can re-purposed them for these hooks, they screw into any of the holes on the sides of the self.
I've stored a full costco bag of onions on these hooks for a few weeks, no issues.
The author hasn't provided the model origin yet.