Place the beans in a large bowl or pot and cover with water by 2 inches. Let soak for 8 hours or overnight. Drain and set aside.
In a large pot, heat the bacon grease over medium-high heat. Add the tasso and cook, stirring for 1 minute.
Add the onions, celery and bell peppers to the grease in the pot.
Season with the salt, pepper and cayenne, and cook, stirring until the vegetables are soft, about 4 minutes.
Add the bay leaves, parsley, thyme, sausage, and ham hocks and cook stirring, to brown the sausage and ham hocks, about 4 minutes.
Add the garlic and cook for 1 minute.
Add the beans and stock or water, stir well, and bring to a boil.
Reduce the heat to medium-low and simmer, uncovered, stirring occasionally, until the beans are tender and starting to thicken, about 2 hours.
(Should the beans become too thick and dry, add more water, about 1/4 cup at a time.) Remove from heat and with the back of a heavy spoon, mash about 1/4 of the beans against the side of the pot. Continue to cook until the beans are tender and creamy, 15 to 20 minutes. Remove from heat and remove the bay leaves.
