1/2 c. all-purpose flour 2 large eggs, whisked Kosher salt and freshly ground black pepper 1 c. panko breadcrumbs 1 oz. Parmesan, grated (about 1/4 cup) 2 large tomatoes, cut into 8 (1/2-inch) slices 1 c. canola oil 1/2 c. mayonnaise 8 slices sourdough bread, toasted 1 avocado, sliced 8 slices cooked bacon 4 romaine leaves
Place flour and eggs in separate shallow bowls. Season with salt and pepper. Place panko and Parmesan in a third shallow bowl. Season with salt and pepper. Season tomatoes with salt and pepper.
Heat oil in a large, straight- sided or cast-iron skillet over medium-high heat. Place a wire rack on a rimmed baking sheet.
Dip tomatoes in flour, then egg (allowing excess to drip off), then panko mixture, pressing to help adhere. Fry, in two batches, turning once, until golden brown, 4 to 5 minutes. Transfer to wire rack.
Spread mayonnaise on bread, dividing evenly.
Top four pieces of bread with avocado, bacon, romaine, and tomatoes, dividing evenly. Top with remaining 4 slices of bread.