Soak the beans (optional but recommended): Place the dried beans in a large bowl and cover with at least 3 inches of cold water. Soak overnight, or for a quick soak, cover with water, bring to a boil for 2 minutes, then remove from heat, cover, and let stand for 1 hour. Drain and rinse.

In a large Dutch oven or heavy-bottomed pot over medium heat, add the sliced andouille sausage. Cook until browned and some fat has rendered, about 5-7 minutes. Remove half the sausage and set aside for later.

To the pot with the remaining sausage and fat, add the diced onion, bell pepper, and celery (the 'Holy Trinity'). Cook, stirring occasionally, until softened, about 8-10 minutes. Add the minced garlic, thyme, smoked paprika, and cayenne, cooking for 1 more minute until fragrant.

Add the drained beans, bay leaves, and 6 cups of broth or water to the pot. Bring to a boil, then reduce heat to a low simmer. Cover partially and cook until the beans are very tender and the liquid has thickened, stirring occasionally, for 1.5 to 2 hours. In the last 30 minutes, add the reserved cooked sausage back to the pot.

Once beans are tender, season generously with salt and black pepper. For a creamier texture, mash about one cup of the beans against the side of the pot with a spoon and stir—this acts as a natural thickener.

Discard the bay leaves. Spoon the creamy beans and sausage over a bed of fluffy white rice. Garnish with sliced green onions.