Carla Hall's Superfast Seafood Stew with Fish and Shrimp

This is a recipe that I tried from Carla Hall's new cookbook "Carla Hall's Soul Food: Everyday and Celebration." This is a fast recipe and I was able to prepare part of it (steps 1-3 below) before dinner and then right before dinner, completed step 4 and folded in the fish. I made a few variations to make it dairy and shell-fish free so that my daughter with allergies could eat it too. I also added in chopped leek since I had some extra in my fridge.

Ingredients:

• 2 tablespoons unsalted butter (used olive oil)
• 2 tablespoons all-purpose flour
• 1 tablespoon vegetable oil
• 2 andouille sausage links, thinly sliced
• 1 onion, diced
• 1 stalk celery, diced (used 3 stalks)
• 1 poblano chili, seeded and diced (omitted)
• 1 green bell pepper, seeded and diced
• Kosher salt and freshly ground pepper
• 2 large garlic cloves, minced
• 2 fresh thyme springs (used dry thyme)
• 1 bay leaf (used 2 bay leaves)
• 2 tablespoons Seafood Seasoning (used Old Bay seasoning)
• 1 cup clam juice
•  1 ear corn, kernels cut, cob reserved (omitted, but want to use can corn next time)
• 1 pound white fish fillets, cut into 2 inch chunks (used 10 oz tilapia) 
• 1 pound shell-on deveined shrimp (omitted) 
• Scallions, for garnish

Directions

1. Melt butter in a small saucepan over medium heat. Add the flour and cook, stirring often until dark brown, about 10 minutes. Remove the roux from heat. 
2. Meanwhile, heat the oil in a large Dutch oven over medium heat. Add the sausage and cook, stirring often until browned, 2 to 3 minutes. Transfer to a plate. Add the onion, celery, chile, bell pepper and 1/2 teaspoon salt. Cook, stirring often, until just tender, about 5 minutes. Add the garlic and cook, stirring, for 3 minutes. Add the thyme, bay leaf, seafood seasoning, and 1/4 teaspoons black pepper. Cook, stirring for 2 minutes.
3. Add the clam juice, 3 cups water, the corncob, and the browned sausage with any accumulated juices. Bring to a boil, then reduce the heat to simmer steadily. Stir in the roux, then simmer for 10 minutes. Discard the corncob, thyme sprigs, and bay leaf. 
4. Fold in the fish and shrimp, making sure they're submerged in the liquid. Cover and simmer over medium heat, stirring occasionally, until just cooked through, about 7 minutes. Stir in the corn kernels.
5. Divide among the bowls and garnish with scallions.