This gadget claims to deliver perfectly cubed onions and elegant batons of carrots, bell peppers, or apples with one punch of the hand-held chopper’s blades against its platform base. The tool did chop half a small yellow onion (and even cut it into a fine dice, after some careful rotation and a second chomp). But with a larger red-onion half, and then a medium-sized carrot, the operation failed: We found ourselves cautiously extracting suspended vegetables from the blades and poking leftover bits through the grid with the tines of a fork.