Container system for microwave cooking

In a metal container for use in a microwave or convection oven as well as for packaging and storage of a foodstuff to be subsequently cooked therein in a microwave or convection oven wherein the container includes a metallic substantially smooth, wrinkle-free, continuously extending peripheral sidewall portion that is contiguous with a metallic, substantially smooth and wrinkle-free bottom portion and further having a substantially smooth and wrinkle-free peripheral edge portion extending continuously adjacent an outermost terminal portion of said sidewall portion and wherein said sidewall portion is provided in elevation with an outwardly and upwardly curving configuration of substantial radius to produce an overall height of said container member not exceeding one inch and said metal container in plan view being provided with a rounded configuration with substantial radius or with a polygonal configuration including rounded corners of substantial radius with the substantial radii being sufficient to substantially reduce the concentration of microwave energy in a microwave oven environment, and wherein said sidewall portion, including said edge portion, has both the inner and outer surfaces thereof coated with a film of electrically insulating plastic material of a film thickness on the order of 0.25 to 2.25 mils with said plastic material being effective to withstand the heat of cooking and to diffuse and thereby prevent substantial reflection of microwave energy, the improvement comprising:

• said bottom portion including an opening therein of a size to admit microwave energy and a microwave transparent insert of generally convex form overlying said opening said microwave transparent insert being affixed to said metallic container continuously about said periphery of said opening and being disposed with respect to said bottom portion to project upwardly within the metal container whereby the container is of a maximum depth outside said periphery of said opening and is of a lesser depth within said periphery of said opening.