According to the present invention there is provided a flexible container for use by the end user as a cooking utensil. Said container comprises a front and rear panel formed of a food safe material and sealed at three sides, the rear panel being extended beyond the front panel on the unsealed fourth side to form a flap. On the upper side of the flap is formed an adhesive strip provided with a removable cover strip intended to be removed by the user when closing the container. The user is instructed to fold the container across both layers rather than simply across the junction of the flap and front panel in order to seal it prior to cooking. This creates a container which is effectively sealed but which is capable of releasing excess pressure above that level needed to steam the contents thoroughly. At the opposite end and sides of the container, away from the flap, a second weld parallel to the sealed edge may be formed on one or more sides in order to create an area which is not subject to the steam effect which occurs when food is heated, thus forming a cooler area for handling by the user when the product is cooked and removed from the microwave oven.