Melt butter in a sizable, deep skillet over low heat before stirring in flour. About 10 minutes of continual stirring is required to achieve a dark caramel hue.

Continue stirring for another 5 minutes or until the onions, peppers, and celery are tender. Add salt, pepper, and Cajun seasoning after incorporating the garlic and sausage. Bring to a boil while stirring in the bay leaf, diced tomatoes, and chicken broth. Simmer for about an hour while stirring regularly on low heat to thicken.

Add shrimp 10 minutes before serving. Taste the shrimp once it is pink and fully cooked, then adjust the seasonings. Green onions are added while some are saved for garnish.

Spoon over white rice when serving.