A cooking tool such as a small, round glass disk is manufactured which rattles in the pan as the water boils, thus making a sound to indicate the boiling point has been reached. Other solutions include small ceramic or clay-like disks designed to lie in the bottom of pots and pans that actually help to prevent the water from foaming out over the pan as it boils. The disks may be produced as a round disk or be formed into the shape of a food item for marketing purposes only, but regardless of shape, the material contained in the disk does effectively work to prevent water or liquids from boiling over.