Add the beans to a large container and cover them with water.
Soak the beans overnight, for about 8 hours, until doubled in size. Drain.
Heat the oil in a large pot over medium heat.
Add the andouille sausage and sear until browned on either side, about 5 minutes.
Remove the sausage, reserving the grease in the pot.
Add the pepper, onion, and celery and cook until soft, about 5 minutes. Add the garlic and stir until fragrant.
Add the beans and the ham hock to the pot, then return the sausage to the pot and cover with stock. Add the bay leaves, thyme, and pepper.
Bring to a boil, then cover and reduce to a simmer. Simmer for 2 ½ hours, stirring occasionally, until the beans are tender and the mixture is creamy.
Once the beans are soft, remove the pot from the heat and remove the ham hock. Shred the meat from the ham hock, discarding any bones or cartilage, and return the pork to the pot.
Add salt to taste (you may not need any). Then, to serve, top with scallions and parsley.