An apparatus includes a lower vessel and an upper vessel mounted atop the lower vessel. The lower vessel, which can be disposed on the heated surface of a stove, includes a first top wall having apertures therethrough, and defines a first volume in the lower vessel. The upper vessel includes a second top wall free of apertures, and defines a second volume in the upper vessel. Food items to be cooked are placed on the first top wall so that the food item resides in the second volume. Heat from the heated surface rises into the first volume, through the apertures and into the second volume, to cook the food item therein. Means are provided for maintaining the vertical stability of the vessels when the vessels are stacked.