To a large pot, add olive oil, onion, celery, bell pepper, and garlic. Stir and sauté over medium heat for 5 minutes, until vegetables are softened.
Chop sausage into bite sized pieces and add to the pot. Stir and continue to cook about 5 more minutes to lightly brown the sausage.
Add dry kidney beans to a bowl along with water. Rinse the beans then drain.
Add the rinsed beans to the pot along with cajun seasoning and all broth.
Stir, cover, and cook over medium heat for 4-6 hours, stirring every 30-45 minutes.
The beans will eventually burst, creating a smooth velvety texture as shown in the photos.
If the beans get too thick, add more broth and continue to low cook until the beans reach a texture you prefer. If the beans are too thin and broth still exists, they are not done and need to continue cooking.
Serve over rice, top with Tobasco sauce, and enjoy!