01 - Heat the vegetable oil in a large Dutch oven or heavy pot over medium heat. Add the sausage and ham hock (if using); cook until the sausage is browned, about 5 minutes. Remove sausage and set aside, leaving the rendered fat in the pot.
02 - Add onion, bell pepper, and celery to the pot. Cook, stirring often, until softened, about 5 minutes. Stir in garlic and cook for 1 minute more.
03 - Return the sausage to the pot. Add soaked and drained beans, ham hock (if removed), bay leaf, thyme, paprika, cayenne, black pepper, oregano, and salt. Pour in the chicken stock or water and bring to a boil.
04 - Reduce heat to low, cover, and simmer gently for 1.5 to 2 hours, stirring occasionally, until beans are tender and the mixture is creamy. If the liquid reduces too much, add a little more water as needed.
05 - Combine rice, water, and salt in a saucepan. Bring to a boil, then cover and reduce heat to low. Cook for 15-18 minutes, or until water is absorbed and rice is tender. Remove from heat and let sit, covered, for 5 minutes. Fluff with a fork.
06 - Remove the ham hock and bay leaf from the beans. If desired, mash some beans against the side of the pot for a creamier texture. Adjust seasoning with salt and hot sauce to taste.
07 - Serve the red beans over a mound of hot white rice. Garnish with spring onions and parsley. Offer extra hot sauce on the side.