Abstract: A strainer which may be adapted to fit over an opening of a variety of food storage and preparation containers comprising a flexible matrix, a flexible cord which is slidably disposed within a conduit, said conduit being located along the perimeter of said matrix and having an opening through which the ends of said cord protrude, and a means for releasably engaging the ends of said cord, wherein after said strainer is placed over the opening of the container, the ends of said cord are pulled through said engaging means to adapt the circumference of the conduit to that of the container, said cord being engaged when said conduit contacts the container.