01 - Rinse rice under cold water until water runs clear. Bring 3 cups water and 1/2 tsp salt to a boil in a medium saucepan. Add rice, stir once, reduce heat to low, cover, and simmer for 15 minutes. Remove from heat, let stand covered for 5 minutes, then fluff with a fork.
02 - Melt butter in a large skillet or Dutch oven over medium heat. Sprinkle in flour and stir continuously to form a roux. Cook, stirring constantly, until roux reaches a light caramel color, approximately 5-7 minutes.
03 - Add chopped onion, bell pepper, and celery to the roux. Sauté for 5 minutes until vegetables are softened. Stir in minced garlic and cook for 1 minute until fragrant.
04 - Stir in diced tomatoes, Cajun seasoning, smoked paprika, dried thyme, cayenne pepper, bay leaves, and a generous pinch of salt and black pepper. Mix thoroughly to distribute seasonings evenly.
05 - Gradually pour in stock while stirring constantly to prevent lumps from forming. Bring mixture to a simmer and cook for 10 minutes, stirring occasionally to maintain consistency.
06 - Add crawfish tails to the simmering sauce and cook for 5-7 minutes until heated through and flavors have melded. Remove bay leaves and stir in fresh parsley and sliced green onions. Adjust seasoning to taste.
07 - Spoon hot crawfish étouffée over fluffy white rice. Garnish with additional parsley or green onions if desired. Serve immediately while hot.