Baked Flounder with Roasted Tomatoes | The Market at Gus’s

Ingredients

• 6 plum tomatoes, halved lengthwise
• 2 tablespoons olive oil, plus more for one of the baking sheets
• 3/4 teaspoon dried tarragon
• Pinch sugar
• Coarse salt and ground pepper
• 1/3 cup mayonnaise
• 1 tablespoon fresh lemon juice
• 3 slices white sandwich bread (about 1 ounce each), torn into large pieces
• 4 flounder fillets (1 1/2 pounds total)
• 2 tablespoons Dijon mustard