A method for manufacturing a composite material for packaging and tableware is disclosed. The method comprises forming a sheet from a grain-based composition, either by puffing the composition between matrices in a puffing chamber or by extruding a plasticized composition through a die. The resulting sheet, which has a porous matrix, is then laminated on at least one side with a protective film. Lamination may be performed using hot, cold, or wet techniques. The final laminated composite sheet, having a sandwich-type structure, can be cooled, cut into blanks, and subsequently formed into various articles such as trays, plates, and containers.