In a large Dutch oven or heavy-bottomed saucepan, combine melted butter, oil, and flour until smooth.
Cook on medium heat, stirring continuously, for about 10-12 minutes, or until you have achieved the desired color. During this process, don't walk away from the stove because it might burn.
Add the onion, green pepper, and celery, and cook for 8-10 minutes – stirring frequently.
Then add garlic, thyme, and bay leaf - continue stirring about 2 minutes longer.
Next, throw in about 1 cup chopped tomatoes, Worcestershire sauce, paprika, and Creole seasoning, and let it cook for 5 minutes.
Gradually pour in about 2 cups of shrimp stock, bring to a boil, and let it simmer. Add the shrimp and simmer for 5 more minutes. Or you may season the shrimp with Creole seasoning, sauté for about 5 minutes, and then throw it in at the last minute. You've got two options here - both work.
Adjust the soup's thickness and flavor with more shrimp broth or water, hot sauce, and salt.
Stir in the green onions and chopped parsley.
Serve over hot cooked rice.