Treebeard’s is a Houston institution. I love to eat there and always  have red beans and rice. I found this yummy recipe at Food.com It is really close to the original.

Ingredients-
1 lb dried red kidney beans
2 quarts water
2 medium onions, chopped
2 stalks celery, with leaves, chopped
1/2 large bell pepper, chopped
1 1/2 teaspoons salt
1 1/2 teaspoons thyme
1 1/2 teaspoons oregano
1 1/4 teaspoons garlic powder
1/4 teaspoons cayenne pepper (you can always add more)
2 bay leaves
1 lb smoked sausage, cut in 1/2 inch slices

Directions-
1-Sort and wash red beans. In a large soup pot, add 2 quarts cold water and red beans. Let soak overnight. (To speed up process, you can bring them to a boil, simmer 2 minutes, remove from heat and let stand 1 hour before the next step). DO NOT DRAIN WATER!

2-Add onions, celery and bell pepper to beans and bring to a boil. Cover and reduce heat to simmer about 1 1/2 hours, or until beans are soft . Do not stir more than necessary.

3-Stir in seasonings and sausage. Simmer 30 minutes more. Remove the bay leaves.

4-Meanwhile cook a pot of rice and serve the beans over hot cooked rice, garnished with shredded cheddar cheese and chopped green onion.

5- Don’t stir more than necessary because you don’t want mushy beans. If you want thicker beans remove the lid during the last 30 minutes of cooking time or remove 1/2 cup of the beans and mash them before returning to the pot.