Place a large Dutch oven over medium-low heat. Add butter or oil. If using butter, let it melt completely and wait for it to start sizzling slightly.

Sprinkle in flour and begin stirring immediately with a wooden spoon. You’ll notice the roux beginning to thicken up rather quickly.

Stir constantly at this point to prevent it from burning. The roux will start to thin out slightly after a few minutes and you can slow down how often you’re stirring it.

Cook roux over medium-low heat for at least 20 minutes or up to 30 minutes.

Sauté sausage in a separate skillet. Remove sausage from pan once cooked through and let drain on a paper towel lined plate.

Add diced celery, green bell pepper, and onion to the Dutch oven with the homemade roux. Sauté for 6-7 minutes or until vegetables become tender.

Add crushed garlic and continue sautéing for an additional minute.

Pour in broth, tomatoes, and Worcestershire sauce. Stir to combine.

Add thyme, oregano, paprika, cayenne pepper, salt, pepper, and bay leaf. Mix until well combined.

Bring gumbo to a boil. Once ingredients are boiling, reduce heat to a simmer. Allow gumbo to simmer for 35-40 minutes, uncovered, or until it is reduced by almost half.

Add shrimp and sausage. Stir to combine. Continue simmering for 6-7 minutes or until shrimp are cooked through, opaque, and their tails begin to curl.

Remove bay leaf and serve shrimp gumbo over rice with fresh parsley.