Serve fish or chicken with this southern sauce.
In a large saucepan or skillet, heat 2 tbsp. EVOO, two turns of the pan, over medium-high. Add the butter and melt it into the oil. When the butter foams, add the bell pepper, onion, celery, garlic, bay leaf, and thyme. Season with salt and pepper. Cover and cook, stirring occasionally, until the vegetables soften, about 5 minutes. Add the Worcestershire, hot sauce, stock, tomato sauce, and tomatoes. Simmer until the sauce thickens, 10 to 15 minutes. Stir in the scallions.
Season the fish or chicken with salt and pepper and the Old Bay Seasoning. In a large nonstick skillet, heat the remaining 2 tbsp. EVOO, two turns of the pan, over medium-high. If using fish, cook, turning occasionally, until opaque in the center, 7 to 8 minutes. If using chicken, cook, turning occasionally, until cooked through, 8 to 10 minutes.
Transfer the fish or chicken to shallow bowls. Top with lots of sauce. Serve with the baguette.