This is the $12 Ravanello kitchen tool. It turns radishes into little Super Mario mushrooms. You use the center to shave the stem of the mushroom, then a small gouger to poke out the spotted top. It's so simple even a child can do it, provided that child is nothing like me when I was growing up. Whenever my mom asked me to help make dinner I'd always inevitably cut myself, then she'd catch me eating out of the trash. *shrug* The dog taught me stuff.
Keep going for a couple more shots including a picture guide in case you're struggling to understand the concept.
Thanks to hairless, who I trust to make soup without a hair in it. Flies can still go either way.