Heat the oil in a large pot. Add the onion, bell pepper, and celery. Cook until soft and the edges look a little golden.
Add the garlic and stir for one minute until it smells fragrant.
Add the beans, water or broth, smoked paprika, thyme, garlic powder, onion powder, salt, pepper, Creole seasoning, and bay leaf. Stir well.
Bring the pot to a boil, then lower the heat. Cover and simmer for 1 to 2 hours until the beans are soft.
Add the smoked sausage if using. Let it simmer 15 minutes so the flavor blends into the pot.
Use the back of a spoon to mash some of the beans along the side of the pot. This makes the sauce creamy and thick.
Taste and adjust the seasonings. Remove the bay leaf.
Spoon the red beans over hot cooked rice and enjoy.