Soak the dried beans overnight (The beans need to be soaked for at least 12 hours)
Rinse the beans, and place them in the pressure cooker
Peel the onion, and add it to the pressure cooker. (Do not cut it, add it in one piece)
Remove the paper-thin skin surrounding the garlic cloves. Make sure to keep the bulbs intact at the root end so the cloves stay together when trimmed. Trim the top of the cloves. Try not to cut too much of the garlic top so we don't lose all the good flavors.
Add the rest of ingredients
Cover with water, but don't add too much water-- I usually add about two-three fingers of water over the ingredients-Enough to cover them.
Bring to boil, during the first 15-20 minutes, remove any scums that floats to the top.
Once you remove all of the scum, close the pressure cooker and cook for 25 minutes.

Carefully open the pressure cooker
Discard the onion, and the garlic
Transfer all the meat to a bowl
Cut the bacon, chorizo, and blood sausage in smaller pieces.
Serve beans with pieces of meat, and add salt if needed.