Pat the shrimp dry with paper towels. Toss with the olive oil and Cajun seasoning until evenly coated. Set aside while you prepare the sauce. Melt the butter in a large Dutch oven or deep skillet over medium heat. Add the onion, bell pepper, and celery. Cook for 7 to 8 minutes, stirring occasionally, until the vegetables are softened.
Add the garlic and cook for 30 seconds until fragrant. Stir in the tomato paste and cook for 2 minutes, stirring constantly, until it darkens slightly and becomes fragrant.
Add the diced tomatoes, tomato sauce, seafood stock, Worcestershire sauce, hot sauce, thyme, bay leaves, salt, and black pepper. Stir well and bring to a gentle simmer. Cook uncovered for 15 to 20 minutes, stirring occasionally, until the sauce has thickened slightly.
Reduce the heat to low and stir in the seasoned shrimp. Cook for 3 to 5 minutes, just until the shrimp are pink and opaque. Be careful not to overcook them.
Remove the bay leaves and stir in the chopped parsley and sliced green onions. Taste and adjust the seasoning or hot sauce if desired.
Spoon the Shrimp Creole over cooked white rice and garnish with additional parsley. Serve immediately with extra Louisiana-style hot sauce, if desired.