Gumbo, from the Ethiopian word gombo, which means okra, is a classic ingredient used in Louisiana cooking, dating back to French and Spanish settlers and their African slaves. In this case, the gumbo sauce is not thickened with okra, but with filé powder, which is made from the ground roots of a sassafras tree.
1/3 cup vegetable oil
1/2 cup all-purpose flour
11/2 pounds halibut fillet
2 tablespoons unsalted butter
1 medium onion, diced
1/2 green bell pepper, seeds and ribs removed, and diced
1 celery rib, diced
3 garlic cloves, minced
1 large egg
2 cups fish stock or bottled clam juice, divided
1/2 cup plain breadcrumbs
Salt and freshly ground black pepper to taste
1 tablespoon fresh thyme or 1 teaspoon dried
2 bay leaves
1 (14-ounce) can diced tomatoes, undrained
1/2 teaspoon hot red pepper sauce or to taste
1 tablespoon filé powder
1. Preheat the oven to 450° F. Combine oil and flour in a Dutch oven, and place the pan in the oven. Bake roux for 20 to 30 minutes, or until walnut brown, stirring occasionally.
2. Rinse halibut, pat dry with paper towels, and cut into 1-inch pieces. Place halibut cubes on a sheet of plastic wrap, and freeze for 20 to 30 minutes, or until firm but not frozen solid.
3. While roux bakes, heat butter in large skillet over medium-high heat. Add onion, green pepper, celery, and garlic. Cook, stirring frequently, for 3 minutes, or until onion is translucent. Set aside.
4. Whisk egg and 2 tablespoons fish stock in a mixing bowl, add breadcrumbs, and mix well. Chop halibut in a food processor using on-and-off pulsing. Add halibut to the mixing bowl, season to taste with salt and pepper, and mix well again. Chill mixture for at least 30 minutes.
5. Remove roux from the oven, and place the Dutch oven on the stove over medium heat. Add fish stock, and whisk constantly, until mixture comes to a boil and thickens. Add vegetable mixture, thyme, bay leaves, and tomatoes to pan. Season to taste with hot red pepper sauce, salt, and pepper. Bring to a boil, cover, and cook over low heat for 20 minutes, uncovered, stirring occasionally.
6. Make fish mixture into 1-inch balls, and gently lower them into simmering sauce using a slotted spoon. Bring to boil, then reduce the heat to low, cover the pan, and simmer fish balls for 25 minutes, turning them gently with a slotted spoon after 15 minutes. Remove and discard bay leaves. Remove the pan from the heat, and stir in filé powder. Stir well, season to taste with salt and pepper, and serve immediately. Do not allow the mixture to boil or the filè powder will become stringy.
Note: The fish mixture can be prepared up to 1 day in advance and refrigerated, tightly covered. Also, the dish can be cooked up to 2 days in advance and refrigerated, tightly covered. Reheat, covered, over low heat until hot.