Heat the oil in a large sauce pan over medium heat add the sausage and saute until lightly golden brown, about 5-7 minutes, and set aside.Add the onions, celery and green pepper to the pan and cook until tender, about 7-10 minutes.Add the garlic and cook until fragrant, about 1-2 minutes.Add the stock, beans, ham hock, sausage, paprika, cayenne, oregano, thyme, bay leaves, salt and pepper and bring to a boil.Reduce the heat to medium-low and simmer covered for at least 1 hour continuing for another hour or two if you have the time to bring out more flavour from the ham hock.Remove the ham hock, pull the meat from it, cut it into bite sized pieces and add it back to the pot if desired.Mash or puree about a quarter of the beans.Serve over rice.