Wash, peel, and chop all the vegetables. Set aside.

Sprinkle flour over the oxtail pieces and coat them lightly. Set aside.

Heat extra virgin olive oil in the pressure cooker and sear the oxtail pieces. If needed, do this in two batches for convenience. Set aside.

Gradually add the vegetables to the pot and cook over medium heat for about 10 minutes with the lid loosely on top.
Add the smaller pieces of oxtail and mix well so the flavors combine, cooking for another 5 minutes.

Add the remaining oxtail pieces and mix. Then add the wine and bay leaves. Close the pressure cooker and heat on high until it reaches pressure.
Cook over medium heat for 50 minutes.

Once the pressure has released, open the cooker, add the chopped chocolate, and stir as it melts. With the cooker open, cook for another 20-25 minutes over medium heat. If the meat is already tender, 10 minutes is enough to thicken the sauce.

Remove the meat and place it on a serving platter or plate.

Use a blender to puree the vegetables. You can add more black pepper if you like.
Pour the sauce over the meat, sprinkle with chopped fresh parsley, and serve.