I often reiterate that when cooking meats in a pressure cooker you want to use the natural pressure release method (pot comes to atmospheric pressure on its own as the temperature lowers).  This is because the Natural Pressure Release allows the juices within the meat to redistribute so when you cut the meat the juice stays with the meat and not all over your cutting board.  However, this recipe calls for Quick Pressure release (carefully and manually moving the pressure relief valve from sealing to venting) because since this is a soup and the meat will be swimming in liquid, there is no need for the juices to redistribute!  Always use extreme caution when using the quick-release pressure option!