Judge SS onion chopper
I bought on of these after the miserable failure of 'Delia's chopper'.
It was not expensive and had plenty of good reviews.
I'm afraid my experience has not been as positive. Onions need to be cut into fairly small pieces first or it just jams. A medium-sized onion first has to be cut in half, then into smaller pieces and each 'half' chopped separately.
It is a pest to clean unless completely dismantled. I would say that I am very mechanically-minded yet 50% of the time, I manage to re-assemble it incorrectly. Eventually the grey plastic insert snapped, rendering it useless.
The failure was very possibly due to my incorrect re-assembly, however that is ultimately a design fault, not mine.
When it worked, it worked well, but ultimately a knife is way quicker and cleaning a knife takes seconds.