Place a large pot, I use a Dutch Oven on medium-high heat. Add the water and bring it to a boil. Next add the shrimp shells, Better than Bouillon, and 1/2 teaspoon of Creole Seasoning.
Stir and cover. Lower heat and simmer for 20 minutes.
Open the pot and strain the shells from the broth using a strainer. Set the broth aside.
Add the olive oil and butter to a skillet on medium-high heat. Once it melts add the flour.
Continue to whisk until the roux turns peanut butter brown (or your desired shade of brown). It should turn brown within a few minutes of whisking. Watch it closely so that it doesn't burn. A peanut butter brown roux will take 5-6 minutes of stirring. A deep brown roux (as shown in the photos of this recipe) will take you 10 minutes or more. Set the roux aside to cool.
Add the green peppers, celery, and onions to the Dutch Oven on medium-high heat with a teaspoon of olive oil. Stir and cook for 2-3 minutes until the veggies are soft.
Add the roux and garli to the pot and stir. Saute for 1-2 minutes.
Add all of the seasonings, 2 cups of the seafood broth, and Worcestershire sauce to the pot.
Stir and cover. Reduce the heat and simmer for 15 minutes.
Open the pot and add the shrimp. Cook for 3-4 minutes until the shrimp has turned pink. Remove the bay leaves and remove the pot from heat. Serve with white rice.
The use of Better than Bouillon Seafood Base is optional, but it gives the stock more flavor.
When making the roux, if the oil and flour mixture is thick, add more oil.
Instead of using a combination of butter and oil for the roux, you can use all butter if you wish.
You can purchase seafood stock as opposed to making your own, if you can find it in stores.
Whether tomatoes are used or not in Louisiana cooking is always a source of debate. Most Cajun recipes do not include tomatoes during the cooking process. A lot of Creole recipes use tomatoes. You can decide what will work best for you.