In a large cast-iron Dutch oven, heat oil over medium-high heat. Add sausage, onion, bell pepper, and celery; cook until sausage begins to brown, about 5 minutes. Add stock, beans, reserved 1 cup potlikker, Cajun seasoning, and hot sauce; bring to a boil. Add rice. Cover; reduce heat, and simmer until rice is tender, about 20 minutes. Garnish with parsley, if desired.
Recipe by Southern Cast Iron at https://southerncastiron.com/quick-red-beans-and-rice/