Season fillets with salt and pepper and place them in a lightly greased shallow baking dish. Broil about 8 to 10 inches away from the heat source until lightly browned. To prepare sauce, process the vinegar with the next 4 ingredients in a food processor or blender until well blended. While motor is running, add oil in a thin stream until emulsified. Season to taste with additional salt and pepper. To serve, drizzle room temperature sauce over warm fish.