Rinse and sort beans.
Turn pressure cooker to saute and add half the oil. Add sausage or ham and saute until browned, approximately five minutes, and remove.
Add additional oil and cook onion, celery, bell pepper and garlic until onions are soft and translucent.
Add meat back to the pot, along with the beans, water or stock, parsley, salt and pepper, and bay leaf and stir.
Switch pressure cooker to manual setting and close/lock lid in place. Set the manual timer for 40 minutes.
When the pressure cooker is finished, allow the pressure to release naturally for at least 20 minutes before turning the valve to release the rest of the pressure.
Remove lid and stir. You may also use the back of a spoon to mash some beans for a thicker consistency. Add salt and pepper if needed, and serve over rice.