A tool 10, 60, or 100 used to hold a bagel 22 upright while being sliced from edge to edge with a blade 28 of a knife 30. Each tool 10, 60, and 100 includes a base 12 having a top surface 12a adapted to support the bagel 22 by an edge of the bagel 22. An upright support plate 14 is removably mounted to the base 12 and has opposed lateral sides and opposed faces 14a ad 14b. A pair of knife blade guides 16 and 18 are attached to the base 12 opposite each other, each guide being positioned near one of the opposed sides of the upright support plate 14 and spaced apart to provide therebetween a cutting zone 24. A positioning structure regulates the thickness of the sliced segments of the bagel 22, and includes the upright support plate 14. By removal of the support plate and reversing the position of the support plate by remounting in a reverse orientation, the positions of the faces 14a and 14b are reversed, with the one face that was initially next to the cutting zone 24 changing its position and the other face being moved to the cutting zone 24.