Melt the butter over medium heat in a large skillet or sauté pan.
Add the diced onion, green bell pepper, celery, and minced garlic to the skillet. Cook them in the skillet until they become soft and smell good.
Sprinkle the all-purpose flour over the vegetables and butter. Stir well to combine, ensuring the flour coats the vegetables evenly.
Cook the flour and vegetable mixture, stirring constantly, for about 5 minutes. This helps cook off the raw flour taste and creates a roux with a golden color.
Slowly pour in the seafood stock or chicken broth while stirring continuously. This will help incorporate the liquid into the roux without creating lumps.
Add the diced tomatoes (including the liquid) and tomato paste to the skillet. Mix everything by stirring well.
Season the mixture with Cajun seasoning, paprika, thyme, oregano, cayenne, salt, and black pepper. Adjust the seasonings according to your taste preferences and desired level of spiciness.
Turn the heat low and let the sauce cook gently for 15-20 minutes.
While the sauce is simmering, prepare the shrimp by peeling and deveining them if necessary. Rinse the shrimp with cold water and gently dry them with a paper towel.
The shrimp to the simmering sauce, stirring gently to coat them with the sauce. Cook the shrimp for about 5-7 minutes or until they turn pink and are cooked through. Ensure not to cook the shrimp for too long, as they can become tough and chewy.
After the shrimp are cooked, take the skillet off the stove.
Serve the Shrimp Etouffee Pappadeaux over cooked white rice. Spoon the shrimp and sauce mixture over the rice.
Garnish with chopped green onions or parsley, if desired, to add a fresh touch to the dish.