Combine all ingredients in a stovetop or electric pressure cooker and cover with cold water, about 2 quarts . Make sure not to let liquid exceed the cooker's max-fill line; it's okay if a few things poke above the water's surface. Close cooker and bring to high pressure, then cook at high pressure for 45 minutes. Allow cooker to depressurize, either by allowing it to cool to room temperature or by using the pressure-release valve on the cooker to rapidly vent steam. Skim fat from stock, strain, then use as desired or freeze for up to 6 months.
