1. Heat oil in a large Dutch oven over medium heat. Gradually add flour and stir constantly with a wooden spoon to form a roux. Cook for 20–30 minutes until the mixture turns a deep chocolate brown.

2. Add chopped onion, bell pepper, and celery. Cook until softened, then add garlic and stir for another minute.

3. Stir in andouille sausage and let it brown slightly in the roux.

4. Slowly pour in the stock, stirring to dissolve the roux into the liquid. Add Cajun seasoning, bay leaves, thyme, Worcestershire sauce, and hot sauce if using. Simmer uncovered for 45 minutes.

5. Add shrimp and crab meat (if using). Simmer for about 5 minutes, or until the shrimp turn pink.

6. Remove from heat. Stir in green onions and parsley.

7. Serve hot over cooked white rice.