A commercial cooking apparatus is provided for simultaneous steaming and two-sided grilling of food items having non-uniform thickness and/or variations in nominal thickness. The apparatus includes a compressible, heat-resistant ring member, and optionally a flexible, non-stick, heat-resistant film material associated with the ring member to form a cavity defined by the inner perimeter of the ring member. A cooking method is also disclosed, wherein a food item and a quantity of water are introduced into the cavity, and the food item is simultaneously cooked by the heated upper and lower platens of a conventional clamshell grill or similar apparatus and by steam generated by heating the water.
