Heat a large heavy-bottomed pot or Dutch oven over high heat, add the oil and heat through. Whisk the flour into the hot oil to make the roux. Lower the heat to medium-low and continue to whisk until the roux becomes a deep brown color, about 10 minutes.

Add the onions, reduce the heat to medium-low and cook until the onions caramelize, about 4 minutes. Add the celery, bell pepper, jalapeño and garlic, cooking until the vegetables become soft, about 5 minutes. Add the tomato then stir in the thyme, paprika, cayenne and the shellfish stock, increasing the heat to medium.

Bring the mixture to a boil, then reduce the heat to medium-low and simmer, stirring occasionally, until the mixture thickens, about 10 minutes.

Add the crawfish tails and stir in the Worcestershire and hot sauce and cream. Season with salt and pepper as needed. Ladle the mixture into soup bowls and top with a scoop of rice. Garnish with green onions and parsley.