A disposable insert or liner conformable to a slow cook cookware (such as, for example, a conventional crock pot or like slow cooking device) having a single interior cooking chamber. The liner is adapted to fit within the interior chamber of a crockpot so as to substantially be in adjacent contact with the crock pot interior chamber walls without interfering with the operation of the cooking device. The liner provides a single compartment which may be made of any material allowing heat conduction between the cookware and the liner. A suitable material may be a tear resistant aluminum foil to withstand typical food preparation in a crock pot. In one embodiment, the present invention includes a flange, notches, indentations or other formations which assist in the insertion and removal of the present invention in the cookware. The present invention advantageoiusly provides for a desirable cooking environment, allows easy removal of food from the crock pot and provides simplified cleaning of the crock pot.