A package has a seal portion that includes steam passage portions for externally releasing steam from inside the tray. The steam passage portion has an inner edge in which the portions configuring one side and the other side relative to the tip are curved and extended nearing each other toward the tip. The steam passage portion has an outer edge in a curved shape with a pointed tip, the shape being similar to that of the inner edge. The steam passage portion has a merging portion located between the tip of the outer edge and the tip of the inner edge, and a non-merging portion located between the merging portion and a common portion. The non-merging portion has a width narrowed from the common portion toward the merging portion.

The invention proposes to dispense a substance from a container filled with a single portion of a substance. The container comprises a preformed deformable body defining a filling cavity which body has an opening and an integral planar circumferential rim surrounding said opening. The opening is closed by a cover sheet which is sealed to the circumferential rim by a circumferential sealing seam. The circumferential rim has a dispensing part which is covered by the cover sheet. A dispensing passage is formed between the dispensing part and the cover sheet. At the location of the dispensing passage is provided a weakened sealing seam portion, such that upon pressurizing the content of the container, the weakened sealing seam portion breaks and substance flows out of the container through the dispensing passage. The dispensing part is flat and the dispensing passage for the substance is defined by the cover sheet sealed to the flat dispensing part by at least two outwardly directed sealing seams. The outwardly directed sealing seams extend at a distance from one another from the circumferential sealing seam to the edge of the dispensing part.