1-1/2 Cups Roux [see below]
2 Cups diced onion
1 Cup diced celery
1 Cup diced green bell pepper
1 Tbsp finely chopped garlic, or minced garlic
2 quarts shrimp, crab or chicken stock
1 lb Andouille sausage, sliced into 1/4-inch thick rounds, browned in a skillet, and drained
2 Bay Leaves
1 Tbsp Worcestershire sauce or 1 tsp Worcestershire Powder
Dash hot sauce like Tabasco
1/4 tsp Cayenne Pepper
1-1/2 tsp salt
3/4 tsp freshly ground Black Pepper
2 lb medium shrimp, peeled and deveined
1/2 lb lump crabmeat
1/3 Cup green onion tops, chopped
1/2 Cup coarsely chopped parsley leaves
2 Tbsp chopped fresh thyme leaves, or 1 Tbsp dried thyme
1 Tbsp chopped fresh basil leaves, or 2 tsp dried basil
1/2 Cup File Powder, or to taste
Steamed White Rice, for serving
Make the Roux:
3 Cups fat [lard or vegetable oil]
5 Cups all-purpose flour
Using a heavy Dutch oven or cast iron skillet with deep sides, heat fat over medium heat until just-smoking. Whisk in flour, a little at a time and cook, whisking constantly so that mixture is not lumpy. Roux will become smooth and thick.
Continue to cook, constantly stirring with a wooden spoon and reaching all over bottom of pan, until roux darkens to desired color.
Make the Gumbo:
Transfer 1-1/2 cups of the roux to a medium-sized heavy stockpot over medium-high heat. Once hot, add the onions, celery and bell pepper, and stir mixture until onions begin to brown, about 5 minutes. Add the garlic and continue to cook for 1 minute.
Slowly pour in stock, whisking constantly to prevent lumps from forming. Add the browned sausage, bay leaves, Worcestershire, hot sauce, cayenne, salt, and pepper.
Turn up the burner and bring your gumbo to a boil, reduce heat to medium and simmer with stock pot lid askew until gumbo is slightly reduced, about 45 minutes.
Stir in the shrimp, crabmeat, green onions, parsley, thyme and basil. Cook until shrimp are cooked through, about 5 minutes. Sprinkle in file powder and cook, stirring, 2 minutes more. In some southern homes and restaurants, diners pass the file at the table instead, for folks to thicken their gumbo as desired.
Serve in big soup bowls over steamed white rice.