Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the onion, green bell pepper, and celery. Sauté for about 5-7 minutes until softened and aromatic.

Stir in 2 cloves of minced garlic and cook for 1 minute until fragrant. Add 2 tablespoons of all-purpose flour, stirring constantly for 1-2 minutes until lightly browned.

Gradually whisk in 2 cups of chicken broth, ensuring no lumps form. Stir in 1 cup of heavy cream, 2 tablespoons of Creole seasoning, 1 tablespoon of Worcestershire sauce, and cayenne if desired. Simmer for 5-7 minutes until thickened.

Add 1 tablespoon of butter to the sauce if using. Place the seasoned red snapper fillets in the sauce, cover, and cook for 5-7 minutes until the fish flakes easily with a fork.

Remove from heat, stir in 2 tablespoons of chopped parsley, and serve immediately over fluffy cooked rice.