A microwave energy interactive heating sheet (100a, 100b) comprising: at least two plies (102, 104) of a microwave energy interactive insulating material arranged in a superposed, layered configuration, the at least two plies of microwave energy interactive insulating material being at least partially joined to one another along respective peripheral edges to define a cavity for receiving a food item, wherein each ply of microwave energy interactive insulating material includes a susceptor film comprising a microwave energy interactive material supported on a first polymer film layer, a moisture-containing layer superposed with the microwave energy interactive material, and a second polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable insulating cells between the moisture-containing layer and the second polymer film layer, wherein at least some of the expandable insulating cells are operative for inflating when the microwave energy interactive heating sheet is exposed to microwave energy, wherein the heating sheet (100a, 100b) is adapted for being used in two configurations, wherein in a first configuration, the food is positioned within the cavity, and in a second configuration, with the food item removed from the cavity, the at least two plies of microwave energy interactive insulating material are in a superposed, contacting relationship beneath the food item with one or more of the peripheral edges bulging upwardly along the sides of the food item upon exposure to microwave energy. at least two plies (102, 104) of a microwave energy interactive insulating material arranged in a superposed, layered configuration, the at least two plies of microwave energy interactive insulating material being at least partially joined to one another along respective peripheral edges to define a cavity for receiving a food item, wherein each ply of microwave energy interactive insulating material includes a susceptor film comprising a microwave energy interactive material supported on a first polymer film layer, a moisture-containing layer superposed with the microwave energy interactive material, and a second polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable insulating cells between the moisture-containing layer and the second polymer film layer, wherein at least some of the expandable insulating cells are operative for inflating when the microwave energy interactive heating sheet is exposed to microwave energy, a susceptor film comprising a microwave energy interactive material supported on a first polymer film layer, a moisture-containing layer superposed with the microwave energy interactive material, and a second polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable insulating cells between the moisture-containing layer and the second polymer film layer, wherein at least some of the expandable insulating cells are operative for inflating when the microwave energy interactive heating sheet is exposed to microwave energy, wherein the heating sheet (100a, 100b) is adapted for being used in two configurations, wherein in a first configuration, the food is positioned within the cavity, and in a second configuration, with the food item removed from the cavity, the at least two plies of microwave energy interactive insulating material are in a superposed, contacting relationship beneath the food item with one or more of the peripheral edges bulging upwardly along the sides of the food item upon exposure to microwave energy. in a first configuration, the food is positioned within the cavity, and in a second configuration, with the food item removed from the cavity, the at least two plies of microwave energy interactive insulating material are in a superposed, contacting relationship beneath the food item with one or more of the peripheral edges bulging upwardly along the sides of the food item upon exposure to microwave energy.