This is my still-two-years-old-for-another-month daughter chopping zucchini for dinner (Mommy and Daddy's dinner, since the only vegetables she cares for at the moment are baby carrots and cucumber slices). The tool she is using is called a vegetable crinkle cutter. I'd read about kindergarteners in Waldorf schools chopping vegetables with crinkle cutters to make vegetable soup. The blade is blunt. It requires the child to hold the handle with one hand, and press down with their other hand (see the photo), so little fingers do not get in the way. Again, she is carefully supervised. We've had this tool for a year and I love it.