A pressure steam oven is a specialised oven that cooks food with steam under elevated pressure, combining the gentle, moist heat of steaming with the speed of pressure cooking. Professional combi-steamers offer pressurised steam modes that drive heat into food faster than atmospheric steamers, cutting cooking times for large joints, batch vegetables, and grains while preserving moisture, colour, and nutrients. The sealed chamber prevents flavour transfer between foods, so fish and desserts can share a cycle. In food manufacturing, pressure steam ovens and retorts also sterilise canned and pouched foods, the pressure allowing temperatures above 100 °C that destroy Clostridium botulinum spores. The equipment represents the high end of steam cooking technology, where precise control of pressure, temperature, and humidity replaces the guesswork of traditional methods.